RFID tag inlay for incontinence detection pad

ABSTRACT

An absorbent article has one or more fluid filter layers to inhibit electrode traces from being exposed to low volumes of fluid to reduce the number of false positives that are indicated by an RFID tag of the incontinence detection pad. An antenna inlay has a sacrificial trace portion to permit testing for proper operation of an RFID chip electrically coupled to the antenna inlay. After testing, the sacrificial trace portion is severed. A fluid barrier layer blocks fluid from reaching portions of electrode traces that are located on a backsheet outside a periphery of an absorbent core of an incontinence detection pad. The power at which an antenna transmits to wirelessly energize a passive RFID tag of an incontinence detection pad is controlled to reduce the number of false positives indicated by the RFID tag.

The present application claims the benefit, under 35 U.S.C. § 119(e), ofU.S. Provisional Application No. 62/551,565, filed Aug. 29, 2017, U.S.Provisional Application No. 62/648,543, filed Mar. 27, 2018, and U.S.Provisional Application No. 62/660,558, filed Apr. 20, 2018, each ofwhich is hereby incorporated by reference herein in its entirety.

BACKGROUND

The present disclosure relates to incontinence detection systems andparticularly, to incontinence detection systems that use a pad beneath aperson lying in a patient bed. More particularly, the present disclosurerelates to incontinence detection systems that are able to communicatewirelessly between the pad and a reader on the patient bed.

Incontinence detection systems that have incontinence detection padsplaced beneath a patient on a patient bed are known. For example, U.S.Pat. No. 5,537,095 discloses an incontinence detection pad havingelectrical circuitry that couples via a wired connection to a controllerof a patient bed. Recent efforts have involved the development ofwireless communication between the circuitry of the incontinencedetection pad and a reader on a patient bed. See, for example, U.S.Patent Application Publication Nos. 2017/0065464 A1 and 2017/0246063 A1,and International Publication No. WO 2017/087452 A1 each of which ishereby incorporated by reference herein for all that it teaches.

Some incontinence detection pads include a layer having electrodesprinted thereon and a passive radio frequency identification tag coupledto the electrodes. It is sometimes the case that false positive alertsare generated due to perspiration or medicinal gels, lotions, or creamsleeching through the incontinence detection pad and coming into contactwith the electrodes. In such situations the patient's skin may act aspart of the electrical pathway between the electrodes in combinationwith the leeched moisture that contacts the electrodes. Accordingly,there is a need to eliminate the number of false positive alerts thatoccur in the prior art incontinence detection pads. Other improvementsin incontinence detection pads and readers are also desirable.

SUMMARY

The present application discloses one or more of the features recited inthe appended claims and/or the following features which, alone or in anycombination, may comprise patentable subject matter:

According to the present disclosure, an absorbent article may include atopsheet that may be made of a fluid permeable material and a backsheetthat may include a first layer of fluid impermeable material. Aconductive ink pattern may be provided above the first layer and may beconfigured to form a first electrode trace and a second electrode trace.A passive radio frequency identification (RFID) tag may be attached tothe first layer and may have electrical contacts that may couple to thefirst and second electrode traces. An absorbent core may be situatedbetween the topsheet and the backsheet. A fluid filter layer may besituated so as to inhibit a low volume of fluid from being able to reachthe first and/or second electrode traces beneath the absorbent core.After fluid of a sufficient volume greater than the low volume haspassed through the topsheet, the absorbent core, and the fluid filterlayer, an electrical pathway may be formed between the first and secondelectrode traces by the fluid which may enable the passive RFID tag toemit a signal that may indicate an incontinence event has occurred inresponse to the passive RFID tag being excited by external energy.

In some embodiments, the fluid filter layer may include a hydrophobicpolymeric nonwoven material or a hydrophilic material. The hydrophobicpolymeric nonwoven material may include, for example, one or more of thefollowing: a spunbond material, a spunlace material, a meltblownmaterial, or a meltspun material. Alternatively or additionally, thehydrophobic polymeric nonwoven material may include a polypropylene orpolyethylene material that may have a pore size and basis weight thatmay be configured to prevent the low volume of fluid from penetratingtherethrough due to surface tension of the fluid.

In some embodiments, the fluid filter layer may include a perforatedfilm. Optionally, the perforated film may include one or more of thefollowing: die cut holes, laser cut holes, or holes created by vacuumforming. Further optionally, the perforated film may include one or moreof the following: low density polyethylene (LDPE), high densitypolyethylene (HDPE), polyethylene terephthalate (PET), or polypropylene.In some embodiments, the conductive ink pattern above the first layermay be printed on an underside of the perforated film. In suchembodiments, the holes of the perforated film may all be spaced apartfrom the conductive ink pattern printed on the underside of theperforated film.

In some embodiments, the fluid filter layer may include an adhesivematerial that may be applied to a bottom of the absorbent core or to thebacksheet. The adhesive material may include a hot melt adhesive or apolyethylene powder that is thermally bonded to the filter layer andabsorbent core or backsheet as the case may be. For example, theadhesive material may be applied to the bottom of the absorbent core orto the backsheet so as to match a geometry of the first and/or secondelectrode traces thereby covering the respective first and/or secondelectrode traces. If desired, the adhesive material may include a hotmelt adhesive. Alternatively of additionally, the adhesive material maycomprise an adhesive film or may be spray coated on the bottom of theabsorbent core. Further alternatively or additionally, the adhesivematerial may be slot coated on the bottom of the absorbent core. Theadhesive material may be configured to have a first width greater than asecond width of the first and second electrode traces so that adhesivematerial may extend beyond opposite sides of the first and secondelectrode traces. The first width may be from about 3 millimeters (mm)to about 25 mm and the second width may be about 1 mm. The first widthmay be defined by a shim of a slot coater that is used to apply theadhesive.

In some embodiments, the fluid filter layer may include a hydrophobiccoating applied to the absorbent core. The hydrophobic coating may beapplied in one or more of the following patterns: dots, stripes, orrandom pattern. The hydrophobic coating may be sprayed onto theabsorbent core or applied as an adhesive film.

In some embodiments, the fluid filter layer may include a solublecoating that may be applied over the first and second electrode traces.For example, the soluble coating may include a water soluble coating.Alternatively or additionally, the soluble coating may include a urinesoluble coating. Optionally, the soluble coating may include adissolvable ink. The soluble coating may be absent from portions of thefirst and second electrode traces at which the electrical contacts ofthe passive RFID tag may couple to the first and second electrodetraces.

Alternatively or additionally, the fluid filter layer may include acellulosic nonwoven material. For example, the cellulosic nonwovenmaterial may include tissue paper.

If desired, the fluid filter layer may be situated above the absorbentcore. Optionally, the fluid filter layer also may be situated above thetopsheet. Alternatively, the fluid filter layer may be situated beneaththe topsheet. Further alternatively, the fluid filter layer may besituated beneath the absorbent core.

In some embodiments, a first outer periphery of the fluid filter layermay be coextensive with a second outer periphery of the absorbent core.Alternatively or additionally, a first outer periphery of the fluidfilter layer may be coextensive with a second outer periphery of thetopsheet. Further alternatively or additionally, a first outer peripheryof the fluid filter layer may be coextensive with a second outerperiphery of the backsheet. Optionally, the fluid filter layer may belaminated to the absorbent core using one or more of the following:adhesive, heat bonding, or latex bonding.

In some embodiments, the fluid filter layer may include an adhesive withdesiccant media. The adhesive with desiccant media may adhere thetopsheet to the absorbent core, for example. Alternatively oradditionally, the fluid filter layer may include a desiccant. Forexample, the desiccant may be sprayed onto the topsheet or the absorbentcore or the backsheet.

If desired, the adhesive also may be applied so as to cover asacrificial electrode trace portion that may be on the backsheet inspaced apart relation with the first and second electrodes. For example,the adhesive also may be applied to portions of the first and secondelectrode traces that may extend beyond a periphery of the absorbentcore.

According to another aspect of the present disclosure, a method ofmanufacturing a passive RFID tag may include attaching an RFIDintegrated circuit chip to a first antenna inlay of a backsheet that maycarry a plurality of antenna inlays. Each antenna inlay may include anantenna portion, a pair of electrical contact portions, and asacrificial connecting portion that may interconnect the pair ofelectrical contact portions. The RFID integrated circuit chip may haveelectrical contacts that may electrically couple to the electricalcontact portions of the first antenna inlay when the RFID integratedcircuit chip is attached to the backsheet. The method may furtherinclude emitting energy to provide the RFID integrated circuit chip withpower via the antenna portion of the first antenna inlay, receiving areturn signal from the RFID integrated circuit chip transmitted via theantenna portion of the first antenna inlay, and processing the returnsignal from the RFID integrated circuit chip to confirm that the RFIDintegrated circuit chip may be working properly due to the return signalindicating that the respective pair of electrical contact portions andthe respective sacrificial connection portion of the first antenna inlayform a completed short circuit. The method may further include cuttingthe backsheet material at a location which may sever at least a part ofthe sacrificial connecting portion from the pair of electrical contactportions of the first antenna inlay to place the pair of electricalcontact portions of the first antenna inlay in an open circuitconfiguration and leaving the part of the sacrificial connecting portionbehind on a portion of the backsheet that may be associated with aneighboring antenna inlay.

In some embodiments, at least one of the electrical contacts of the RFIDintegrated circuit chip may include a tamper input.

According to a further aspect of the present disclosure, an antennainlay may include an antenna portion, a first electrical contactportion, and a second electrical contact portion. The first electricalcontact portion may include a first electrical lead that may have afirst gap formed therein to provide a first lead segment and a secondlead segment. A first resistor may be placed across the gap toelectrically interconnect the first and second lead segments.

In some embodiments, the second electrical contact portion may include asecond electrical lead that may have a second gap formed therein toprovide a third lead segment and a fourth lead segment. A secondresistor may be placed across the second gap to electricallyinterconnect the third and fourth lead segments. Optionally, the secondelectrical contact portion may be configured as a mirror image of thefirst electrical contact portion.

In some embodiments including those having just the first gap or thosehaving both the first and second gaps, the antenna portion, firstelectrical contact portion, and the second electrical contact portionmay be coplanar. For example, the antenna portion, first electricalcontact portion, and the second electrical contact portion comprise ametallic film. The metallic film may comprise aluminum. Optionally, athickness of the metallic film may be about 9 micrometers (μm).Alternatively or additionally, the antenna portion may include a firstantenna patch and a second antenna patch. If desired, the second antennapatch may be configured as a mirror image of the first antenna patch.

In some embodiments having both of the first and second gaps, the firstresistor and the second resistor may have substantially equivalentresistances or the first resistor and the second resistor may havedifferent resistances. For example, the resistance of at least one ofthe first and second resistors may be about 2.4 Mega Ohms (MΩ). In oneembodiment, the resistance of one of the first and second resistors maybe about 2.4 MΩ and the resistance of the other of the first and secondresistors may be about 1.0 MΩ.

According to yet another aspect of the present disclosure, an absorbentarticle may include a topsheet that may be made of a fluid permeablematerial, a backsheet that may include a first layer of fluidimpermeable material, and a conductive ink pattern that may be providedabove the first layer and that may be configured to form a firstelectrode trace and a second electrode trace. A passive radio frequencyidentification (RFID) tag may be attached to the first layer and mayhave electrical contacts that may couple to the first and secondelectrode traces. An absorbent core may be situated between the topsheetand the backsheet. The absorbent core may have a first periphery thatmay be inboard of a second periphery of the topsheet and inboard of athird periphery of the backsheet. A first portion of the first electrodetrace may extend beyond the first periphery and a second portion of thesecond electrode trace may extend beyond the first periphery. A fluidbarrier layer may be situated over the first portion of the firstelectrode trace and over the second portion of the second electrodetrace so as to inhibit fluid from being able to reach the first andsecond portions of the respective first and second electrode traces thatmay extend beyond the periphery of the absorbent core. After asufficient volume of fluid has passed through the topsheet and theabsorbent core, an electrical pathway may be formed between the firstand second electrode traces by the fluid which may enable the passiveRFID tag to emit a signal that may indicate an incontinence event hasoccurred in response to the passive RFID tag being excited by externalenergy.

In some embodiments, the fluid barrier layer may include an adhesivematerial that may be applied over the first portion and the secondportion of the respective first and second electrode traces outboard ofthe first periphery. For example, the adhesive material may be appliedto a bottom surface of the topsheet or to a top surface of thebacksheet. Optionally, the adhesive material may include a hot meltadhesive. Further optionally, the adhesive material may be applied tothe top surface of the backsheet by a slot coating process. For example,the slot coating process may use a shim that may have a first set ofopenings of a first width and a second set of openings each having asecond width that may be larger than the first width. The secondopenings may be in registry with the first and second portions of therespective first and second electrode traces. In some embodiments, thefirst width may be about 1 mm and the second width may be from about 3mm to about 25 mm. Optionally, a third width of the first and secondelectrode traces may be about 1 mm and the first and second portions ofthe first and second electrode traces may be generally centered withinthe second width such that adhesive material may extend beyond oppositesides of the first and second portions of the respective first andsecond electrode traces. The first width may be defined by a shim of aslot coater that may be used to apply the adhesive.

In some embodiments, a portion of the fluid barrier layer may extendover a part of the first and second electrode traces inboard of thefirst periphery of the absorbent core. In some embodiments, the secondperiphery of the topsheet may be substantially coextensive with thethird periphery of the back sheet.

In some embodiments, the absorbent article may further include a fluidfilter layer that may be situated so as to inhibit a low volume of fluidfrom being able to reach the first and second electrode traces beneaththe absorbent core. The fluid filter layer may include a hydrophobicpolymeric nonwoven material or a hydrophilic material. For example, thehydrophobic polymeric nonwoven material may include one or more of thefollowing: a spunbond material, a spunlace material, a meltblownmaterial, or a meltspun material. Alternatively or additionally, thehydrophobic polymeric nonwoven material may include polypropylene orpolyethylene material having a pore size and basis weight configured toprevent the low volume of fluid from penetrating therethrough due tosurface tension of the fluid.

In some embodiments, the fluid filter layer may include a perforatedfilm. For example, the perforated film may include one or more of thefollowing: die cut holes, laser cut holes, or holes created by vacuumforming. Alternatively or additionally, the perforated film may includeone or more of the following: low density polyethylene (LDPE), highdensity polyethylene (HDPE), polyethylene terephthalate (PET), orpolypropylene. If desired, the holes of the perforated film all may bespaced apart from the conductive ink pattern that may form the first andsecond electrode traces.

In some embodiments, the fluid filter layer may include an adhesivematerial that may be applied to a bottom of the absorbent core or to thebacksheet. For example, the adhesive material may be applied to thebottom of the absorbent core or to the backsheet so as to match ageometry of the first and/or second electrode traces thereby coveringthe respective first and/or second electrode traces beneath theabsorbent core. Optionally, the adhesive material may include a hot meltadhesive. Alternatively or additionally, the adhesive material maycomprise an adhesive film or may be spray coated on the bottom of theabsorbent core. If desired, the adhesive material may be slot coated onthe bottom of the absorbent core. The adhesive material may beconfigured to have a first width that may be greater than a second widthof the first and second electrode traces so that adhesive material mayextend beyond opposite sides of the first and second electrode traces.For example, the first width may be from about 3 mm to about 25 mm andthe second width may be about 1 mm.

In some embodiments, the fluid filter layer may include a hydrophobiccoating that may be applied to the absorbent core. For example, thehydrophobic coating may be applied in one or more of the followingpatterns: dots, stripes, or random pattern. If desired, the hydrophobiccoating may be sprayed onto the absorbent core or applied as an adhesivefilm.

In some embodiments, the fluid filter layer may include a solublecoating that may be applied over at least a portion of the first andsecond electrode traces. For example, the soluble coating may include awater soluble coating. Alternatively or additionally, the solublecoating may include a urine soluble coating. Further alternatively oradditionally, the soluble coating may include a dissolvable ink. Thesoluble coating may be absent from portions of the first and secondelectrode traces at which the electrical contacts of the passive RFIDtag may couple to the first and second electrode traces.

In some embodiments, the fluid filter layer may include a cellulosicnonwoven material. For example, the cellulosic nonwoven material maycomprise tissue paper.

In some embodiments, the fluid filter layer may be situated above theabsorbent core. In such embodiments, the fluid filter layer also may besituated above the topsheet. Alternatively, the fluid filter layer maybe situated beneath the topsheet. On the other hand, the fluid filterlayer may be situated beneath the absorbent core.

In some embodiments, a fourth periphery of the fluid filter layer may becoextensive with the first periphery of the absorbent core.Alternatively or additionally, a fourth periphery of the fluid filterlayer may be coextensive with the second periphery of the topsheet.Alternatively, a fourth periphery of the fluid filter layer may becoextensive with the third periphery of the backsheet. If desired, thefluid filter layer may be laminated to the absorbent core using one ormore of the following: adhesive, heat bonding, or latex bonding.

In some embodiments, the fluid filter layer may include an adhesive withdesiccant media. The adhesive with desiccant media may adhere thetopsheet to the absorbent core, for example.

In some embodiments, the fluid filter layer may include a desiccant.Optionally, the desiccant may be sprayed onto the topsheet or theabsorbent core or the backsheet.

If desired, the adhesive also may be applied so as to cover asacrificial electrode trace portion that may be on the backsheet inspaced apart relation with the first and second electrodes. Optionally,the adhesive of the fluid filter layer also may be applied to first andsecond portions of the respective first and second electrode traces thatextend beyond the first periphery of the absorbent core.

According to still a further aspect of the present disclosure, a methodof controlling an incontinence detection system includes establishing afirst antenna of a plurality of antennae as a transmit antenna that maybe used to wirelessly energize a passive RFID tag of an absorbentarticle at a first power level. The plurality of antennae may include Nspaced apart antennae and N may be an integer equal to or greater thanthree. The method may further include establishing each of the pluralityof antennae, except for the first antenna, as receive antennae that eachmay listen for backscattered data that may be emitted from the passiveRFID tag. The method may further include reducing the first power levelto a second power level if the receive antennae that are able to readthe backscattered data exceeds a predetermined number of receiveantennae and the predetermined number may be less than N−1.

In some embodiments, the method may further include analyzing signal tonoise ratio between the transmit antenna and each of the receive antennabefore reducing the first power level to the second power level.Alternatively or additionally, the method may further include analyzinga receive signal level (RSL) figure of merit (FoM) of the backscattereddata before reducing the first power level to the second power level.Optionally, the RSL FoM of multiple emissions of backscattered data maybe averaged before reducing the first power level to the second powerlevel. Further alternatively or additionally, the method may furtherinclude determining that an external power flag may be set in thebackscattered data before reducing the first power level to the secondpower level.

In some embodiments, the predetermined number of receive antennae mayinclude two receive antennae. Alternatively, the predetermined number ofreceive antennae may include one receive antenna. In some embodiments,the first power level and the second power level lie within a range ofabout +20 decibel milliWatt (dBm) to about +33 dBm.

In some embodiments, the method may further include cycling through theplurality of antennae as being established as the transmit antenna witheach of the remaining antennae of the plurality of antennae beingestablished as the receive antenna for a period of time. Optionally, theplurality of antennae may be coupled to a bistatic radio frequency (RF)switch matrix which may be operable to establish which antenna of theplurality of antennae is the transmit antenna and to establish whichantenna of the plurality of antennae is the receive antenna. The methodmay further include operating the bistatic RF switch matrix to cause thetransmit antenna to transmit using a frequency hopping scheme. Thefrequency hopping scheme may uses 50 distinct frequencies, for example,with each frequency being used only once in a pseudo-random order beforeany of the 50 frequencies are repeated. In some embodiments, the 50frequencies may lie within a range between about 902 MegaHertz (MHz) and928 MHz.

According to yet a further aspect of the present disclosure, anabsorbent article may include a topsheet that may be made of a fluidpermeable material, a backsheet that may include a first layer of fluidimpermeable material, an absorbent core that may be situated between thetopsheet and the backsheet, and an insert layer that may be situatedbetween the backsheet and the absorbent core. The insert layer mayinclude a substrate, a conductive ink pattern that may be provided onthe substrate and that may be configured to form a first electrode traceand a second electrode trace. A passive radio frequency identification(RFID) tag may be provided on the substrate and may have electricalcontacts that may couple to the first and second electrode traces.

In some embodiments, the substrate may include paper or a cellulosicnonwoven material or tissue paper, for example. If desired, thebacksheet may further include a second layer of nonwoven material. Thefirst and second layers of the backsheet may be coupled together with ahot melt adhesive. Alternatively or additionally, the backsheet mayfurther include a second layer of polypropylene and, optionally, thesefirst and second layers of the backsheet may be coupled together with ahot melt adhesive.

In some embodiments, the absorbent article may further include a fluidfilter layer that may be situated between the absorbent core and theinsert layer. The fluid filter layer may be configured to inhibit a lowvolume of fluid from being able to reach the first and second electrodetraces on the substrate of the insert layer. After fluid of a sufficientvolume greater than the low volume has passed through the topsheet, theabsorbent core, and the fluid filter layer, an electrical pathway may beformed between the first and second electrode traces by the fluid whichmay enable the passive RFID tag to emit a signal that may indicate anincontinence event may have occurred in response to the passive RFID tagbeing excited by external energy.

Optionally, the fluid filter layer may include a hydrophobic polymericnonwoven material or a hydrophilic material. For example, such ahydrophobic polymeric nonwoven material may comprise one or more of thefollowing: a spunbond material, a spunlace material, a meltblownmaterial, or a meltspun material. If desired, the hydrophobic polymericnonwoven material may include a polypropylene or polyethylene materialhaving a pore size and basis weight that may be configured to preventthe low volume of fluid from penetrating therethrough due to surfacetension of the fluid.

Also according to the present disclosure, an absorbent article mayinclude a topsheet that may be made of a fluid permeable material, anabsorbent core that may be situated beneath the topsheet, a substratethat may be situated beneath the absorbent core, a conductive inkpattern that may be provided on the substrate and that may be configuredto form a first electrode trace and a second electrode trace, and apassive radio frequency identification (RFID) tag that may be attachedto the substrate and that may have electrical contacts that may coupleto the first and second electrode traces. The first and second electrodetraces each may have a redundancy means for coupling to the electricalcontacts of the passive RFID tag to provide redundant electricalpathways between the first and second electrode traces and theelectrical contacts.

In some embodiments, the redundancy means may include portions of thefirst and second traces that each may have a ladder geometry. The laddergeometry of each of the first and second traces may have a pair ofelongated sides and a series of rungs that may interconnect therespective elongated sides. Some or all of the rungs may besubstantially perpendicular to the elongated sides. Alternatively oradditionally, some or all of the rungs may not be perpendicular to theelongated sides such that the rungs each may extend between theelongated sides at an inclined angle.

In some embodiments, the ladder geometry of the first trace may besubstantially parallel with the ladder geometry of the second trace.Furthermore, the ladder geometries of the first and second traces mayhave substantially equivalent lengths. Optionally, the ladder geometryof the first trace may be offset along its length compared to the laddergeometry of the second trace such that first and second ends of theladder geometry of the first trace may not be aligned with first andsecond ends, respectively, of the ladder geometry of the second trace.

Optionally, a first spacing between outer edges of the elongated sidesof the ladder geometry of the first and second electrode traces may beat least three times a width of portions of the first and secondelectrode traces that are spaced from the ladder geometry. Furtheroptionally, a first spacing between outer edges of the elongated sidesof the ladder geometry of the first and second electrode traces may beat least four times a width of portions of the first and secondelectrode traces that are spaced from the ladder geometry.

Opposite ends of the passive RFID tag each may overlie respective firstelongated sides of the pair of elongated sides of each ladder geometry.In such embodiments, second elongated sides of the pair of elongatedsides of each ladder geometry may be outboard of the respective end ofthe passive RFID tag. If desired, more than one rung of each laddergeometry may extend out and away from the respective end of the passiveRFID tag.

In some embodiments, the ladder geometry may have a length that may beat least three times a width dimension of the passive RFID tag.Optionally, first and second registration marks may be aligned withrespective rungs of the associated ladder geometry and may extendoutwardly from one of the elongated sides of the associated laddergeometry to indicate a mid-region of the length of the ladder geometryat which the passive RFID tag may be aligned when attached to thesubstrate.

In some embodiments, the redundancy means may include end regions of thefirst and second electrode traces that may be wider than portions of thefirst and second electrode traces that are spaced from the end regions.For example, the end regions may be at least three times wider than theportions of the first and second electrode traces that are spaced fromthe end regions. As another example, the end regions may be at leastfour times wider than the portions of the first and second electrodetraces that are spaced from the end regions.

If desired, the end regions may be formed as solid conductive inkregions. Opposite ends of the passive RFID tag may terminate within theend regions such that portions of the end regions may extend outwardlybeyond the opposite ends of the passive RFID tag. In some embodiments,the end regions of the first and second electrode traces may begenerally straight, the opposite ends of the passive RFID tag may begenerally straight, and the opposite ends of the passive RFID tag may begenerally parallel with the end regions. Optionally, the end regionseach may have a length that is at least three times a width dimension ofthe passive RFID tag.

In some embodiments, the redundancy means may include portions of thefirst and second electrode traces that each may have a comb pattern. Forexample, the comb pattern of the first and second traces each mayinclude an elongated side and a series of teeth extending from arespective elongated side. If desired, the teeth of each comb patternmay extend in substantially perpendicular relation with the respectiveelongated side.

The teeth of the comb pattern of the portion of the first electrodetrace and the teeth of the comb pattern of the portion of the secondelectrode trace may extend toward each other. Opposite ends of thepassive RFID tag each may overlie a plurality of teeth of the respectivecomb pattern and the elongated sides of each comb pattern may beoutboard of the respective end of the passive RFID tag.

In some embodiments, a first width of the comb pattern of the portionsof the first and second electrode traces may be at least three times asecond width of thin portions of the first and second electrode tracesthat are spaced from the respective comb pattern. In some embodiments, afirst width of the comb pattern of the portions of the first and secondelectrode traces may be at least four times a second width of portionsof the first and second electrode traces that are spaced from therespective comb pattern. Optionally, each comb pattern may have a lengththat is at least three times a width dimension of the passive RFID tag.

In some embodiments, the redundancy means may include end regions of thefirst and second electrode traces that are wider than portions of thefirst and second electrode traces that are spaced from the end regions.Optionally, each of the end regions may have a series of holes throughthe conductive ink forming the respective end region such that thesubstrate may be exposed through the series of holes. At least some ofholes of the series of holes of the end regions may be substantiallyquadrilateral in shape. For example, the substantially quadrilateralshape may include at least one of substantially square, substantiallyrectangular, or substantially rhomboid. Alternatively or additionally,at least some of holes of the series of holes may be substantiallycircular in shape.

In some embodiments, each of the end regions may be substantiallystraight and the circular holes may be aligned along a length of thestraight end regions. If desired, each of the end regions may besubstantially straight with each end region having a first elongatedstraight edge and a second elongated straight edge and each circularhole may be located about midway between the first and second elongatedstraight edges of the respective end region. Opposite ends of thepassive RFID tag each may overlie a portion of a plurality of circularholes of each series of circular holes of the respective end region anda portion of each end region may be outboard of the respective end ofthe passive RFID tag.

With regard to the embodiments having holes of other shapes, each of theend regions may be substantially straight and the series of holes ofeach end region may be aligned along a length of the respective endregion. For example, each end regions may be substantially straight witheach end region having a first elongated straight edge and a secondelongated straight edge and each hole of the series of holes may belocated about midway between the first and second elongated straightedges of the respective end region.

In some embodiments, the end regions may be at least three times widerthan portions of the first and second electrode traces that are spacedfrom the end regions. In some embodiments, the end regions are at leastfour times wider than portions of the first and second electrode tracesthat are spaced from the end regions.

Optionally, opposite ends of the passive RFID tag each may overlie aportion of a plurality of holes of each series of holes of therespective end region and a portion of each end region may be outboardof the respective end of the passive RFID tag. The end regions of thefirst and second electrode traces may be generally straight, theopposite ends of the passive RFID tag may be generally straight, and theopposite ends of the passive RFID tag may be generally parallel with theend regions. If desired, the end regions each may have a length that isat least three times a width dimension of the passive RFID tag.

In some embodiments, the redundancy means may include portions of thefirst and second traces that are each configured as an elongated loop.Each elongated loop may include a first elongated segment, a secondelongated segment that may be substantially parallel with the firstelongated segment, and an end segment that may interconnect ends of thefirst and second elongated segments. If desired, opposite ends of thepassive RFID tag may be located over respective spaces betweencorresponding first and second elongated segments of the associatedelongated loop. Optionally, each of the opposite ends of the passiveRFID tag may be straight and substantially parallel with the first andsecond elongated segments of the elongated loops.

In some embodiments, each of the first, second, and end segments mayhave a width of a first dimension thereacross and portions of the firstand second electrode traces spaced from the elongated loops also mayhave widths thereacross substantially equal to the first dimension. Ifdesired, the elongated loops each may have a length that is at leastthree times a width dimension of the passive RFID tag.

In some embodiments of the absorbent articles including the redundancymeans, the substrate may comprise a backsheet that may include a firstlayer of fluid impermeable material and a second layer of nonwovenmaterial and the conductive ink may be provided on the first layer ofthe backsheet. The absorbent article may further include a fluid filterlayer that may be situated so as to inhibit a low volume of fluid frombeing able to reach the first and second electrode traces beneath theabsorbent core.

In some embodiments of the absorbent article including the redundancymeans, a backsheet may be provided beneath the substrate and thesubstrate may comprise an insert layer situated between the backsheetand the absorbent core. The substrate may comprise paper or a cellulosicnonwoven material or tissue paper, for example.

According to still another aspect of the present disclosure, anabsorbent article may include a substrate, a first electrode on thesubstrate, a second electrode on the substrate, the second electrode maybe spaced from the first electrode, and circuitry that may be coupled tothe first and second electrodes. The circuitry may be operable tomonitor whether a biofluid may be present on the substrate bydetermining whether the first and second electrodes are in an opencircuit configuration or a closed circuit configuration. The opencircuit configuration may be indicative of an absence of biofluid and aclosed circuit configuration may be indicative of a presence ofbiofluid. The absorbent article may further include a plurality of highwick bridges that may interconnect the first and second electrodes.

In some embodiments, the first electrode may include a generallystraight first segment, the second electrode may include a generallystraight second segment, and at least some of the high wick bridges mayinclude a generally straight main segment that may be substantiallyperpendicular to the first and second segments. If desired, at leastsome of the high wick bridges may include a series of hash segments thatmay be substantially perpendicular with the main segment. In someembodiments, the main segment may bisect each of the hash segments.Alternatively or additionally, the hash segments may be of substantiallyequivalent lengths.

In some embodiments, the absorbent article may further include ahydrophobic material that may be situated within each of a plurality ofzones bounded by respective portions of the first and second electrodesand by respective pairs of adjacent high wick bridges. The hydrophobicmaterial may comprise a hydrophobic coating, for example. Optionally,the hydrophobic material in at least some of the zones may bequadrilateral in shape. Each of the high wick brides may include a mainsegment and a series of hash segments that may extend across the mainsegment. Ends of the hash segments may terminate at, or may be in closeproximity to, a respective boundary of the hydrophobic material in eachzone. If desired, the circuitry may include a radio frequencyidentification (RFID) tag. For example, the RFID tag may comprise apassive RFID tag.

According to a yet further aspect of the present disclosure, anabsorbent article may include a substrate, a first series of spacedapart hydrophilic fluid guide paths that may be located on a right sideof the substrate, and a second series of spaced apart hydrophilic fluidguide paths that may be located on a left side of the substrate. Thefirst and second hydrophilic guide paths of the first series and secondseries may be mirror images of each other. The hydrophilic fluid guidepaths may be configured to direct moisture away from a patient that maybe situated atop a central region of the substrate.

In some embodiments, each fluid guide path of the first and secondseries of fluid guide paths may extend from the central region of thesubstrate beyond a footprint of the patient's body to a side region ofthe substrate beyond the footprint of the patient's body. Evaporation ofmoisture in the side regions on opposite sides of the footprint mayproduce a moisture gradient within the hydrophilic fluid guide paths sothat moisture within the footprint may move outwardly to the sideregions away from the patient. Alternatively or additionally, pressureproduced on the fluid guide paths by the patient in the central regionmay result in moisture moving outwardly to the side regions away fromthe patient. If desired, the substrate may be generally rectangular inshape and each fluid guide path of the first and second series of guidepaths may be oriented generally along a long dimension of the substrate.The absorbent article may further include a hydrophobic material in acentral region of the substrate.

According to still a further aspect of the present disclosure, anabsorbent article may include a topsheet that may be made of a fluidpermeable material, a backsheet, and a conductive ink pattern that maybe provided above the backsheet and that may be configured to form afirst electrode and a second electrode. The absorbent article mayfurther include a passive radio frequency identification (RFID) tag thatmay be between the topsheet and backsheet and that may have electricalcontacts that may couple to the first and second electrodes. Anabsorbent core may be situated between the topsheet and the backsheetand may be above the first and second electrodes. A first fluid filterlayer may be situated above the first and second electrodes so as toinhibit a low volume of fluid from being able to reach the first and/orsecond electrode beneath the absorbent core. After fluid of a sufficientvolume greater than the low volume has passed through the topsheet, theabsorbent core, and the fluid filter layer, an electrical pathway may beformed between the first and second electrodes by the fluid which mayenable the passive RFID tag to emit a signal indicating an incontinenceevent may have occurred in response to the passive RFID tag beingexcited by external energy. The absorbent article also may have a secondfluid filter layer that may be beneath the first and second electrodes.The second fluid filter layer may inhibit fluid from reaching the firstand second electrodes from below.

In some embodiments, the backsheet may include an upper layer and alower layer and the second fluid filter layer may be situated above theupper layer and below the first and second electrodes. For example, thesecond fluid filter layer may abut an upper surface of the upper layerand the first and second electrodes may be printed on the second fluidfilter layer.

In other embodiments, the backsheet may include an upper layer and alower layer and the second fluid filter layer may be situated betweenthe upper layer and the lower layer of the backsheet. Thus, an uppersurface of the second fluid filter layer may abut a bottom surface ofthe upper layer of the backsheet and a bottom surface of the secondfluid filter layer may abut a top surface of the lower layer of thebacksheet.

In still other embodiments, the backsheet may include an upper layer anda lower layer and wherein the second fluid filter layer may be situatedbeneath the lower layer. For example, an upper surface of the secondfluid filter layer may abut a bottom surface of the lower layer of thebacksheet.

Optionally, the first and/or second fluid filter layers may include ahydrophobic polymeric nonwoven material or a hydrophilic material. Thehydrophobic polymeric nonwoven material may include one or more of thefollowing: a spunbond material, a spunlace material, a meltblownmaterial, or a meltspun material. Alternatively or additionally, thehydrophobic polymeric nonwoven material may include a polypropylene orpolyethylene material having a pore size and basis weight configured toprevent fluid from penetrating the first and/or second fluid filterlayers due to surface tension of the fluid.

If desired, the first fluid filter layer may include a perforated filmand the second fluid filter layer may include a non-perforated film. Theperforated film may include one or more of the following: die cut holes,laser cut holes, or holes created by vacuum forming. The perforated filmand the non-perforated film may include one or more of the following:low density polyethylene (LDPE), high density polyethylene (HDPE),polyethylene terephthalate (PET), or polypropylene. In some embodiments,the conductive ink pattern above the backsheet may be printed on anunderside of the perforated film. In such embodiments, holes of theperforated film all may be spaced apart from the conductive ink patternthat may be printed on the underside of the perforated film.

In some embodiments, the first fluid filter layer may include adhesivematerial that may be applied to a bottom of the absorbent core and/orthe second fluid filter layer may include adhesive material that may beapplied to a surface of the backsheet. Optionally, the adhesive materialmay be applied to the bottom of the absorbent core and to the surface ofthe backsheet so as to match a geometry of the first and secondelectrodes thereby to sandwich the first and second electrodes betweenthe adhesive material. The adhesive material may include a hot meltadhesive or a polyethylene powder that is thermally bonded to the firstand second fluid filter layers, to the absorbent core, and to thesurface of the backsheet.

It is contemplated by this disclosure that the adhesive material mayinclude an adhesive film or may be spray coated on the bottom of theabsorbent core and on the surface of the backsheet. Alternatively oradditionally, the adhesive material may be slot coated on the bottom ofthe absorbent core and on the surface of the backsheet. The adhesivematerial may be configured to have a first width greater than a secondwidth of the first and second electrodes so that adhesive material ofthe first and second fluid filter layers extends beyond opposite sidesof the first and second electrodes. For example, the first width may befrom about 3 millimeters (mm) to about 25 mm and the second width may beabout 1 mm. The first width may be defined by a shim of a slot coaterthat may be used to apply the adhesive.

In some embodiments, the first fluid filter layer may include ahydrophobic coating that may be applied to the absorbent core and/or thesecond fluid filter layer may include a hydrophobic coating that may bedapplied to a surface of the backsheet. The hydrophobic coating may beapplied in one or more of the following patterns: dots, stripes, orrandom pattern. Alternatively or additionally, the hydrophobic coatingmay be sprayed onto the absorbent core and/or the surface of thebacksheet or may be applied as an adhesive film to the absorbent coreand/or the surface of the backsheet.

Optionally, the first fluid filter layer may include a soluble coatingthat may be situated over the first and second electrodes and/or thesecond fluid filter layer may include a non-soluble coating that may besituated beneath the first and second electrodes. For example, thesoluble coating may include a water soluble coating, a urine solublecoating, and/or a dissolvable ink. In some embodiments, the solublecoating may be absent from portions of the first and second electrodesat which the electrical contacts of the passive RFID tag may couple tothe first and second electrodes.

In some embodiments, the first fluid filter layer may include acellulosic nonwoven material and/or the second fluid filter layer mayinclude a cellulosic nonwoven material. For example, the cellulosicnonwoven material comprises tissue paper.

If desired, the first fluid filter layer may be situated above theabsorbent core. Optionally, the first fluid filter layer also may besituated above the topsheet. Alternatively, the first fluid filter layermay be situated beneath the topsheet. Further alternatively, the firstfluid filter layer may be situated beneath the absorbent core.

In some embodiments, a first outer periphery of the first fluid filterlayer may be coextensive with a second outer periphery of the absorbentcore and/or a third outer periphery of the second fluid filter layer maybe coextensive with the second outer periphery of the absorbent core. Inother embodiments, a first outer periphery of the first fluid filterlayer may be coextensive with a second outer periphery of the topsheetand/or a third outer periphery of the second fluid filter layer may becoextensive with the second outer periphery of the topsheet. In furtherembodiments, a first outer periphery of the first fluid filter layer maybe coextensive with a second outer periphery of the backsheet and/or athird outer periphery of the second fluid filter layer may becoextensive with the second outer periphery of the backsheet.

Optionally, the first fluid filter layer may be laminated to theabsorbent core using one or more of the following: adhesive, heatbonding, or latex bonding and/or the second fluid filter layer may belaminated to a surface of the absorbent core using one or more of thefollowing: adhesive, heat bonding, or latex bonding. If desired, thefirst fluid filter layer and/or the second fluid filter layer mayinclude an adhesive with desiccant media. Alternatively or additionally,the first fluid filter layer and/or the second fluid filter layer mayinclude a desiccant. The desiccant may be sprayed onto the topsheetand/or the absorbent core and/or the backsheet.

In some embodiments, the adhesive also may be applied so as to cover asacrificial electrode trace portion that may be situated above thebacksheet in spaced apart relation with the first and second electrodes.Alternatively or additionally, the adhesive also may be applied toportions of the first and second electrodes that extend beyond aperiphery of the absorbent core.

The present disclosure contemplates that the absorbent article of eachof the contemplated embodiments mentioned herein may be of a variety ofdifferent types. For example, the absorbent article may comprise anincontinence detection pad. Such an incontinence detection pad may beplaced between a patient and a mattress of a patient support apparatusthat supports the patient in a healthcare facility. Alternatively, theabsorbent article may comprise an incontinence detection garment such asa diaper. Further alternatively, the absorbent article may comprise afeminine hygiene product.

According to yet another aspect of the present disclosure, an apparatusmay include a backing sheet and a plurality of RFID electrical inlaysthat may be arranged on the backing sheet. Each RFID electrical inlaymay include at least one antenna portion and a pair of electricalcontact portions. Each of the pair of electrical contact portions mayterminate at an electrical contact pad such that one of the electricalcontact pads may be a right pad and such that another electrical contactpad may be a left pad of the respective RFID electrical inlay. Some ofthe RFID electrical inlays may be arranged on the backing sheet inadjacent first and second columns that may have the right pads of thefirst column substantially aligned with the left pads of the secondcolumn such that the right and left pads of the first and secondcolumns, respectively, may be spaced apart and alternate along a firsthypothetical line that may extend through the right and left pads of thefirst and second columns.

In some embodiments, others of the RFID electrical inlays may bearranged on the backing sheet in a third column adjacent the secondcolumn and may have the right pads of the second column substantiallyaligned with the left pads of the third column such that the right andleft pads, of the second and third columns, respectively, may be spacedapart and alternate along a second hypothetical line that may extendthrough the right and left pads of the second and third columns. A firststripe of electrically conductive adhesive may be arranged on thebacking sheet so as to cover the alternating right and left pads of thefirst and second columns. Alternatively or additionally, a second stripeof electrically conductive adhesive may be arranged on the backing sheetso as to cover the alternating right and left pads of the second andthird columns. Further alternatively or additionally, a third stripe ofelectrically conductive adhesive may be arranged on the backing sheet soas to cover the left pads of the first column and, if desired, a fourthstripe of electrically conductive adhesive may be arranged on thebacking sheet so as to cover the right pads of the third column.

Optionally, a width of the first, second, third, and fourth stripes ofelectrically conductive adhesive, if present, may be less than abouttwice a width of the respective right and left pads covered by therespective first, second, third, and fourth stripes of electricallyconductive adhesive. At least one of the first, second, third, andfourth stripes of electrically conductive adhesive may include asubstantially continuous stripe of electrically conductive adhesive.Alternatively, each of the first, second, third, and fourth stripes ofelectrically conductive adhesive may include a continuous stripe ofelectrically conductive adhesive. Further alternatively, at least one ofthe first, second, third, and fourth stripes of electrically conductiveadhesive may include an intermittent stripe of electrically conductiveadhesive.

In embodiments having two columns of RFID electrical inlays, a stripe ofelectrically conductive adhesive may be arranged on the backing sheet soas to cover the alternating right and left pads of the first and secondcolumns. Optionally, the strip of electrically conductive adhesive mayinclude a continuous stripe or an intermittent stripe.

In some embodiments, each of the electrical contact portions may includea left undulated segment and a right undulated segment. A firstsubstantially straight segment may extend substantially perpendicularwith the first hypothetical line and may interconnect the respectiveright pad with the corresponding right undulated segment. A secondsubstantially straight segment may extend at an angle with respect tothe first hypothetical line and may interconnect the respective left padwith the corresponding left undulated segment.

It is contemplated by this disclosure that the left pad of each RFIDelectrical inlay may be located beside the at least one antenna suchthat a second hypothetical line, that may be substantially perpendicularto the first hypothetical line, may extend through a first center of theleft pad and may intersect the at least one antenna. Alternatively oradditionally, the right pad of each RFID electrical inlay may be locatedsuch that a third hypothetical line, that may be substantiallyperpendicular to the first hypothetical line, may extend through asecond center of the right pad and may not intersect the at least oneantenna.

According to still another aspect of the present disclosure, a methodmay include providing a backing sheet that may carry a plurality of RFIDelectrical inlays. Each RFID electrical inlay may include at least oneantenna portion and a pair of electrical contact portions. Each of thepair of electrical contact portions may terminate at an electricalcontact pad such that one of the electrical contact pads may be a rightpad and such that another electrical contact pad may be a left pad ofthe respective RFID electrical inlay. Some of the RFID electrical inlaysmay be arranged on the backing sheet in adjacent first and secondcolumns having the right pads of the first column substantially alignedwith the left pads of the second column such that the right and leftpads of the first and second columns, respectively, may be spaced apartand alternate along a first hypothetical line that may extend throughthe right and left pads of the first and second columns. The method mayfurther include cutting the backing sheet along a cutline that may weaveback and forth between the alternating right and left pads of the firstand second columns.

In some embodiments, after cutting the backing sheet along the cutline,the first column may be separated from the second column and the methodmay further include attaching the first column to a second backing sheetthat may be wider than the first column. If desired, the cutline may besubstantially sinusoidal in shape. Alternatively, the cutline may beshaped as a triangle wave or a square wave.

It is contemplated by this disclosure that, after cutting the backingsheet along the cutline, the first column may be separated from thesecond column and the method may further include cutting the firstcolumn widthwise to separate each of the RFID electrical inlays of thefirst column from one another. The method may further include cuttingthe second column widthwise to separate each of the RFID electricalinlays of the second column from one another.

In some embodiments, prior to cutting the backing sheet along thecutline, the method may include applying electrically conductiveadhesive over the right and left pads of the RFID electrical inlays ofthe first and second columns. For example, applying the electricallyconductive adhesive over the right and left pads of the RFID electricalinlays of the first and second columns may include applying theelectrically conductive adhesive as a substantially continuous stripeover the right and left pads of the RFID electrical inlays of the firstand second columns.

Optionally, some of the RFID electrical inlays may be arranged on thebacking sheet in a third column that may be adjacent the second columnwith the right pads of the second column substantially aligned with theleft pads of the third column such that the right and left pads of thesecond and third columns, respectively, may be spaced apart and mayalternate along a second hypothetical line extending through the rightand left pads of the second and third columns. The method may furtherinclude cutting the backing sheet along a second cutline that weavesback and forth between the alternating right and left pads of the secondand third columns.

In some embodiments, after cutting the backing sheet along the secondcutline, the third column may be separated from the second column andthe method may further include attaching the third column to a secondbacking sheet that may be wider than the third column. If desired, thesecond cutline may be substantially sinusoidal in shape. Alternatively,the second cutline may be shaped as a triangle wave or a square wave.

It is contemplated by this disclosure that, after cutting the backingsheet along the second cutline, the third column may be separated fromthe second column and the method may further include cutting the thirdcolumn widthwise to separate each of the RFID electrical inlays of thethird column from one another. The method may further include cuttingthe second column widthwise to separate each of the RFID electricalinlays of the second column from one another.

In some embodiments, prior to cutting the backing sheet along the secondcutline, the method may include applying electrically conductiveadhesive over the right and left pads of the RFID electrical inlays ofthe second and third columns. For example, applying the electricallyconductive adhesive over the right and left pads of the RFID electricalinlays of the second and third columns may include applying theelectrically conductive adhesive as a substantially continuous stripeover the right and left pads of the RFID electrical inlays of the secondand third columns.

Additional features, which alone or in combination with any otherfeature(s), including those listed above and those listed in the claims,may comprise patentable subject matter and will become apparent to thoseskilled in the art upon consideration of the following detaileddescription of illustrative embodiments exemplifying the best mode ofcarrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the accompanying figuresin which:

FIG. 1 is an exploded perspective view showing layers of an incontinencedetection pad including, from top to bottom, a topsheet of nonwovenmaterial, a layer of slot coated adhesive beneath the topsheet, amoisture absorbent core beneath the layer of adhesive, a low volumefilter layer beneath the absorbent core, a passive radio frequencyidentification (RFID) tag beneath the low volume filter layer, a layerof peripheral hot melt adhesive, and a backsheet having electrodesprinted thereon;

FIG. 2 is an exploded perspective view showing layers of an alternativeembodiment of an incontinence detection pad including, from top tobottom, a topsheet of nonwoven material, a layer of slot coated adhesivebeneath the topsheet, a moisture absorbent core beneath the layer ofadhesive, a layer of peripheral hot melt adhesive, a passive radiofrequency identification (RFID) tag beneath the layer of peripheral hotmelt adhesive, a low volume filter coating, and a backsheet havingelectrodes printed thereon, the low volume filter coating being shapedsubstantially the same as the geometry of the electrodes;

FIG. 3 is a perspective view showing the low volume filter coatingsituated over the electrodes of the backsheet so as to coat theelectrodes;

FIG. 4A is a top plan view of the passive RFID tag on a release linersheet;

FIG. 4B is an exploded side elevation view of the passive RFID tag andrelease liner showing, from top to bottom, a foam layer, a foam-to-tagadhesive layer, a conductive adhesive layer, an inlay film, an inlayantenna, a non-conductive adhesive, and the release liner;

FIG. 4C is a top plan view, similar to FIG. 4A, with the foam layer andfoam-to-tag adhesive removed to expose the inlay antenna andelectrode-to-tamper-input leads;

FIG. 4D is a perspective view showing three passive RFID tags on thesheet of underlying release liner;

FIG. 5A is a top plan view showing a film layer carrying ten antennainlays made of aluminum prior to separation from the film layer forinstallation in the respective RFID tags;

FIG. 5B is a top plan view of one of the antenna inlays of FIG. 5A;

FIG. 5C is an enlarged top plan view of a portion of FIG. 5B showing twogaps formed in tamper input contact leads of the layer of aluminum whererespective resistors are to be attached to the antenna inlay;

FIG. 5D is an enlarged top plan view of a portion of FIG. 5C showingrespective resistors attached to the tamper input contact leads acrossthe gaps;

FIG. 6A is a top plan view of an alternative embodiment of one of theantenna inlays of FIG. 5A;

FIG. 6B is an enlarged top plan view of a portion of FIG. 6A showing twogaps formed in tamper input contact leads of the layer of aluminum whererespective resistors are to be attached to the antenna inlay;

FIG. 6C is an enlarged top plan view of a portion of FIG. 6B showingrespective resistors attached to the tamper input contact leads acrossthe gaps;

FIG. 7A is a top plan view of a second alternative embodiment of one ofthe antenna inlays of FIG. 5A;

FIG. 7B is an enlarged top plan view of a portion of FIG. 7A showing twogaps formed in tamper input contact leads of the layer of aluminum whererespective resistors are to be attached to the antenna inlay;

FIG. 7C is an enlarged top plan view of a portion of FIG. 7B showingrespective resistors attached to the tamper input contact leads acrossthe gaps;

FIG. 7D is an enlarged top plan view of a third alternative embodimentof the antenna inlay showing two gaps formed between widened portionsprovided in tamper input contact leads of the layer of aluminum andshowing respective resistors attached to the widened portions;

FIG. 8 is a top plan view showing two alternative embodiment antennainlays on the respective film, each antenna inlay having a sacrificialshort formed with the tamper input contact leads so that a test forproper functioning of an RFID chip of the passive RFID tag can beundertaken during manufacture prior to severing of the sacrificialshort;

FIG. 9A is a top plan view of an alternative embodiment backsheetshowing the geometry of the electrode traces of the backsheet;

FIG. 9B is an exploded end elevation view of the backsheet of FIG. 9Ashowing, from top to bottom, the backsheet having carbon conductive ink,a breathable low density polyethylene film, a layer of hot meltadhesive, and a layer of polypropylene spunbond nonwoven material;

FIG. 9C is an enlarged top plan view of a portion of FIG. 9A showing atag footprint indicating a location at which the passive RFID tag isattached to the electrodes of the backsheet;

FIG. 10 is a top plan view of the backsheet of FIG. 9A showing a fluidfilter layer of adhesive applied over first and second portions ofrespective first and second electrode traces in a region of thebacksheet located substantially outboard of a periphery of an absorbentcore which is represented by a dotted rectangle;

FIG. 11 is a top plan view, similar to FIG. 10, of the backsheet ofFIGS. 1-3 showing a fluid filter layer of adhesive applied over firstand second portions of respective first and second electrode traces in aregion of the backsheet located substantially outboard of a periphery ofan absorbent core which is represented by a dotted rectangle;

FIG. 12 is a perspective view of a portion of a slot coater shim havinga first set of openings of narrow width and a second opening having awidth that is wider than the narrow width, the second opening being inregistry with a portion of a respective electrode trace;

FIG. 13 is an exploded end elevation view of the incontinence detectionpad of FIG. 1 showing, from top to bottom, the topsheet of nonwovenmaterial, the adhesive beneath the topsheet, a moisture absorbent corebeneath the layer of adhesive, a layer of adhesive beneath the moistureabsorbent core, the low volume filter layer beneath the adhesive, thepassive RFID tag beneath the low volume filter layer, side and endstrips of the layer of peripheral hot melt adhesive, and the backsheet;

FIG. 14A is a top plan view of an alternative embodiment of electrodetrace geometry on a portion of a backsheet where the passive RFID tagcouples to the electrode traces showing end regions of the electrodetraces each having a “ladder” geometry with a series of rungsinterconnecting respective pairs of elongated sides and showing thepassive RFID tag attached to the electrode traces about midway betweenthe top and the bottom of the ladder geometry of the end regions;

FIG. 14B is a top plan view, similar to FIG. 14A, showing the passiveRFID tag attached to the electrode traces at a top portion of the laddergeometry of the end regions;

FIG. 14C is a top plan view, similar to FIGS. 14A and 14B, showing thepassive RFID tag attached to the electrode traces at a bottom portion ofthe ladder geometry of the end regions;

FIG. 14D is an enlarged top plan view of an alternative embodiment of aladder geometry showing rungs being situated at an inclined angle withrespect to the elongated sides of the ladder geometry;

FIG. 14E is an enlarged top plan view of an alternative embodiment of aladder geometry showing rungs being formed by a sinusoidal shapedpattern between the elongated sides of the ladder geometry;

FIG. 14F is an enlarged top plan view, similar to FIG. 14A, showing theladder geometries at the end regions of the first and second electrodetraces being offset generally vertically in the depicted orientationsuch that the upper and lower ends of the ladder geometries of the firstand second electrode traces are not aligned horizontally;

FIG. 15 is a top plan view of another alternative embodiment ofelectrode trace geometry on a portion of a backsheet where the passiveRFID tag couples to the electrode traces showing end regions of theelectrode traces each being larger in width as compared to otherportions of the electrode traces and showing the passive RFID tagcoupled to the larger end regions of the electrode traces;

FIG. 16 is a top plan view of a further alternative embodiment ofelectrode trace geometry on a portion of a backsheet where the passiveRFID tag couples to the electrode traces showing end regions of theelectrode traces each having a “comb pattern” geometry with a series ofteeth extending from a respective elongated side and showing the passiveRFID tag attached to the comb pattern geometry of the end regions;

FIG. 17 is a top plan view of yet another alternative embodiment ofelectrode trace geometry, similar to the embodiment of FIG. 15, on aportion of a backsheet where the passive RFID tag couples to theelectrode traces showing end regions of the electrode traces each havinga series of holes therein and showing the passive RFID tag attached tothe electrode traces at the end regions;

FIG. 18 is a top plan view of still another alternative embodiment ofelectrode trace geometry, similar to the embodiment of FIG. 14A-14C, ona portion of a backsheet where the passive RFID tag couples to theelectrode traces showing end regions of the electrode traces each havingelongated loops and showing the passive RFID tag attached to innersegments of the elongated loop of the electrode traces at the endregions;

FIG. 19 is an exploded perspective view showing layers of an alternativeembodiment of an incontinence detection pad including, from top tobottom, a topsheet of nonwoven material, a moisture absorbent corebeneath the topsheet, a passive radio frequency identification (RFID)tag beneath the moisture absorbent core, an insert layer also beneaththe moisture absorbent core and having electrodes printed thereon, afirst layer of a backsheet beneath the insert layer, and a second layerof the backsheet beneath the first layer of the backsheet;

FIG. 20 is a block diagram of an incontinence detection system includinga plurality of antenna couple to a bed frame, one of the antennaeserving as a transmit antenna to generate a field to power up an RFIDtag of an incontinence detection pad situated between a patient and amattress on the bed frame, and others of the antennae serving as receiveantennae to receive backscattered data from the RFID tag, the antennaebeing coupled to a reader that selects which of the antennae is thetransmit antenna and that adjusts a power level to the transmit antennaeto reduce the power level if the receive antennae that are able to readthe backscattered data exceeds a predetermined number of receiveantennae;

FIG. 21 is a top plan view showing another alternative embodiment of anincontinence detection pad having first and second electrode traces, anumber of hydrophilic bridges interconnecting the first and secondelectrode traces, and hydrophobic zones between the bridges;

FIG. 22 is a top plan view of view of yet another alternative embodimentof an incontinence detection pad having a first series of spaced aparthydrophilic fluid guide paths on a right side of the pad and a secondseries of spaced apart hydrophilic fluid guide paths on a left side ofthe pad, the first and second hydrophilic guide paths being mirrorimages of each other;

FIG. 23 is an exploded perspective view showing layers of an alternativeembodiment of an incontinence detection pad including, from top tobottom, a topsheet of nonwoven material, a layer of slot coated adhesivebeneath the topsheet, a moisture absorbent core beneath the layer ofadhesive, a layer of peripheral hot melt adhesive, a passive radiofrequency identification (RFID) tag beneath the layer of peripheral hotmelt adhesive, a first fluid filter layer, first and second electrodetraces having a geometry similar to that of the first fluid filterlayer, a first option for a location of a second fluid filter layer inthe incontinence detection pad, an upper layer of a backsheet, a secondoption for a location of the second fluid filter layer in theincontinence detection pad, a lower layer of the backsheet, and a thirdoption for a location of the second fluid filter layer, the second fluidfilter layer being shaped substantially the same as the geometry of theelectrodes and the first fluid filter layer;

FIG. 24 is an exploded perspective view, similar to FIG. 23, but showingthree options for the locations of a second fluid filter that isrectangular in shape rather than following the geometry of the first andsecond electrodes;

FIG. 25 is a top plan view of another alternative embodiment backsheetshowing the geometry of the electrode traces of the alternativeembodiment backsheet;

FIG. 26 is a top plan view showing a portion of a film layer carryingsix RFID tag circuits, conductive adhesive stripes extending overelectrical contact pads of the RFID tag circuits, and substantiallysinusoidal cut patterns weaved around the electrical contact pads;

FIG. 27 is a top plan view showing a pair of RFID tag circuits after thesubstantially sinusoidal cuts shown in FIG. 26 have been made, a set oflateral cuts above and below the respective RFID tag circuits, and apair of dashed lines indicating that the RFID tag circuits are placed onan optional wider backing layer after the substantially sinusoidal cutsshown in FIG. 26 have been made;

FIG. 28 is a top plan view showing a first alternative embodiment inwhich a square wave cut pattern is weaved around the electrical contactpads;

FIG. 29 is a top plan view showing a second alternative embodiment inwhich a triangle wave cut pattern is weaved around the electricalcontact pads;

FIG. 30 is a top plan view showing an alternative embodiment in whichthe conductive adhesive is applied, intermittently, as dashes over therespective electrical contact pads;

FIG. 31A is a top plan view of an incontinence detection pad, similar toFIG. 25, showing a substantially rectangular outer perimeter of theincontinence detection pad, a smaller substantially rectangular outlineof an absorbent core of the incontinence detection pad within the outerperimeter, the outline of the electrode traces, a sacrificial trace atthe right hand side of the incontinence detection pad, and the RFID tagattached to ladder-shaped portions of the electrode traces;

FIG. 31B is a top plan view of the incontinence detection pad, similarto FIG. 31A, showing the RFID tag dotted out;

FIG. 31C is a top plan view of the incontinence detection pad, similarto FIG. 31A, showing the sacrificial trace dotted out;

FIG. 31D is a top plan view of the incontinence detection pad, similarto FIG. 31A, showing all portions of the electrode traces, except forthe ladder-shaped portions, in solid and everything else dotted out;

FIG. 31E is a top plan view of the incontinence detection pad, similarto FIG. 31D, but also having the RFID tag in solid;

FIG. 31F is a top plan view of the incontinence detection pad, similarto FIG. 31A, showing the ladder-shaped portions of the electrode tracesin solid and everything else dotted out;

FIG. 31G is a top plan view of the incontinence detection pad, similarto FIG. 31A, showing horizontal portions of the electrode traces insolid and everything else dotted out;

FIG. 31H is a top plan view of the incontinence detection pad, similarto FIG. 31A, showing vertical portions of the electrode traces in solidand everything else dotted out;

FIG. 31I is a top plan view of the incontinence detection pad, similarto FIG. 31G, but having the substantially rectangular outer perimeter ofthe incontinence detection pad shown in solid;

FIG. 31J is a top plan view of the incontinence detection pad, similarto FIG. 31H, but having the substantially rectangular outer perimeter ofthe incontinence detection pad shown in solid;

FIG. 31K is a top plan view of the incontinence detection pad, similarto FIG. 31G, but having the smaller substantially rectangular outline ofthe absorbent core of the incontinence detection pad in solid;

FIG. 31L is a top plan view of the incontinence detection pad, similarto FIG. 31H, but having the smaller substantially rectangular outline ofthe absorbent core of the incontinence detection pad in solid;

FIG. 31M is a top plan view of the incontinence detection pad, similarto FIG. 31G, but having the substantially rectangular outer perimeter ofthe incontinence detection pad shown in solid and having the smallersubstantially rectangular outline of the absorbent core of theincontinence detection pad in solid;

FIG. 31N is a top plan view of the incontinence detection pad, similarto FIG. 31H, but having the substantially rectangular outer perimeter ofthe incontinence detection pad shown in solid and having the smallersubstantially rectangular outline of the absorbent core of theincontinence detection pad in solid.

DETAILED DESCRIPTION

The following description relates to features of incontinence detectionpads that are placed beneath patients on patient support apparatusessuch as hospital beds, stretchers, wheelchairs, chairs, and the like.However, the same features may just as well be implemented in otherabsorbent articles such as incontinence detection garments (e.g.,diapers), feminine hygiene products, and the like. Thus, the descriptionbelow pertains to all types of absorbent articles that absorb and detectbiofluids such as urine or blood, for example.

As shown in FIG. 1, an incontinence detection pad 20 includes, from topto bottom, a topsheet of nonwoven material 22, a layer of slot coatedadhesive 24 beneath the topsheet 22, a moisture absorbent core 26beneath the layer of adhesive 24, a low volume fluid filter layer 28beneath the absorbent core 26, a passive radio frequency identification(RFID) tag 30 beneath the low volume fluid filter layer 28, a layer ofperipheral hot melt adhesive 32, and a backsheet 34 having first andsecond electrodes traces 36 a, 36 b printed thereon. Electrode traces 36a, 36 b are sometimes referred to herein as just “electrodes” or just“traces.” Elements 22, 24, 26, 30, 32, 34, 36 a, 36 b are substantiallythe same as shown and described in International Publication No. WO2017/087452 A1 which is already incorporated by reference herein. Seeparticularly, FIGS. 31-35 and paragraphs 318-327 of InternationalPublication No. WO 2017/087452 A1, in this regard. Thus, fluid filterlayer 28 is an additional element as compared to the incontinencedetection pad embodiments shown and described in InternationalPublication No. WO 2017/087452 A1.

Fluid filter layer 28 is configured to inhibit low volumes of fluid fromreaching electrodes 36 a, 36 b and causing RFID tag 30 to emit a falsepositive signal indicating that an incontinence event has occurred when,in fact, such an event has not occurred. In connection with theillustrative examples contemplated herein in which incontinencedetection pad 20 is used primarily for the detection of urinaryincontinence, low volumes of fluid are considered to be volumes that areabout 40 grams of fluid or less. However, via appropriate selection ofmaterials and geometries for the fluid filter layer 28, other volumethresholds for what is considered to be a low volume of fluid, such asthresholds that are greater than 40 grams or less than 40 grams, arepossible according to the teachings of the present disclosure.

As noted above, false positive alerts are sometimes generated due toperspiration or medicinal gels, lotions, or creams leeching through theincontinence detection pad and coming into contact with the electrodes.In such situations the patient's skin may act as part of the electricalpathway between the electrodes in combination with the leeched moisturethat contacts the electrodes. As used herein, the term “fluid” isintended to cover all fluid or fluid like substances that may come intocontact with incontinence detection pad 20 and complete an electriccircuit between electrode traces 36 a, 36 b, including perspiration,urine, loose feces, lotions, creams, gels, etc. Thus, anything thatisn't a dry substance is within the scope of the term “fluid” accordingto the present disclosure.

Several embodiments are contemplated herein for fluid filter layer 28.In some embodiments, the fluid filter layer 28 includes a hydrophobicpolymeric nonwoven material and in other embodiments, the fluid filterlayer comprises a hydrophilic material. The hydrophobic polymericnonwoven material may include, for example, one or more of thefollowing: a spunbond material, a spunlace material, a meltblownmaterial, or a meltspun material. The hydrophobic polymeric nonwovenmaterial may include a polypropylene or polyethylene material having apore size and basis weight configured to prevent the low volume of fluidfrom penetrating therethrough due to surface tension of the fluid. Forexample, in the case of a spunbond nonwoven material, a basis weight inthe range of about 2 grams per square meter (gsm) to about 50 gsm maysuffice. More particularly, in some embodiments, a basis weight in therange of about 5 gsm to about 20 gsm may suffice. Basis weights aboveand below these ranges are within the scope of the present disclosurefor other embodiments contemplated herein depending upon the desiredfluid transfer properties of the fluid filter layer 28 using spunbondnonwoven material.

Referring now to FIG. 13, an exploded end elevation view of theincontinence detection pad 20 is shown. In the illustrative embodiment,topsheet 22 of pad 20 comprises a polypropylene (PP) spunbond nonwovenlayer, adhesive 24 comprises a layer of hot melt adhesive, absorbentcore 26 comprises an airlaid material, fluid filter layer 28 comprisesan SMS nonwoven barrier layer, and an adhesive layer 27 is providedbetween core 26 and layer 28 and comprises a sprayed layer of hot meltadhesive. Beneath fluid filter layer 28 in FIG. 13 is the RFID tag 30,the peripheral adhesive 32 at the long sides of pad 20 which comprises ahot melt sprayed adhesive, the peripheral adhesive at one end of theshort side of pad 20 which comprises slot coated adhesive, and thebacksheet 34.

A suitable topsheet 22 is Berry 0286 material which is a 17 gsm treatedPP spunbond material available from Berry Global Inc. of Evansville,Ind. According to this disclosure, a series of foot indicia or graphics35 and a series of head indicia or graphics 37 is printed near longedges 44 of topsheet 22 as shown in FIG. 1. Further details of suchgraphics 35, 37 are shown, for example, in FIGS. 59A-62D, 65A-69D, and70 of International Publication No. WO 2017/087452 A1 which is alreadyincorporated by reference herein. A suitable ink for graphics 35, 37 isSun Chemical GA0BG00007 Cool Gray 8C Water-Based ink available from SunChemical of Parsippany-Troy Hills, N.J.

In some embodiments, adhesive 24, 27, 32 is Full Care 5603 hot meltadhesive available from H. B. Fuller Company of St. Paul, Minn. In someembodiments, layer 24 is a lined, combed, slot coated layer havingadhesive applied in rows along the machine direction of topsheet 22 thatare about 1 mm wide and that are spaced apart by about 4 mm. Such lined,combed, slot coating of adhesive 24 results in incontinence detectionpad 20 having a ribbed or furrowed upper surface texture. The ribbedtexture serves to trap any fluid, such as urinary incontinence, on pad20 and to reduce the chances that the fluid will run off pad 20.

In other embodiments, a different combed, slot coating may be used forlayer 24 such as for example, 1 mm glue strips with 1 mm gaps for 50%coverage or 2 mm glue strips with 10 mm gaps for 17% coverage and so on.Peripheral adhesive 32 may be similarly slot coated in any of thesemanners in some embodiments. In some embodiments, adhesive 32 along thelong dimension of pad 20 is spray coated and adhesive 32 along the shortdimension of pad 20 is slot coated. In some embodiments, fluid filterlayer 28 comprises Berry SM10170UN material which is a 17 gsmhydrophobic SSMMS polypropylene (PP) spunmelt nonwoven materialavailable from Berry Global Inc. of Evansville, Ind. Adhesive 27 betweenabsorbent core 26 and fluid filter layer 28 comprises a randomized,sprayed layer in some embodiments. Absorbent core 26 has a weight ofabout 135 gsm and comprises Fitesa B871M135S30 airlaid material in someembodiments.

In some embodiments, absorbent core 26 has a width of about 660 mm+/−20mm between opposite edges 26 a, 26 b as shown in FIG. 13. Fluid filterlayer 28 has a width of about 640 mm+/−10 mm between opposite edges 28a, 28 b. Adhesive layer 27 has a width of about 630 mm+/−5 mm betweenopposite edges 27 a, 27 b. Layers 27, 28 are centered with respect tothe sides 26 a, 26 b and ends of absorbent core 26. Thus, at the nominaldimensions absorbent core 26 overhangs fluid filter layer 28 by about 10mm on each side and overhangs layer 27 by about 15 mm on each side. Asubstantially similar amount of overhang by absorbent core 26 withrespect to the ends of layers 27, 28, respectively, is provided in someembodiments.

In some embodiments, the fluid filter layer 28 includes a perforatedfilm. The holes or perforations provided in the perforated film mayinclude one or more of the following: die cut holes, laser cut holes, orholes created by vacuum forming. The perforated film may include one ormore of the following types of materials: low density polyethylene(LDPE), high density polyethylene (HDPE), polyethylene terephthalate(PET), or polypropylene. In some alternative embodiments, a conductiveink pattern forming electrode traces 36 a, 36 b is printed on anunderside of the perforated film of the fluid filter layer 28 ratherthan being printed on an upper surface of the backsheet 34. In suchembodiments, the holes of the perforated film are all spaced apart fromthe conductive ink pattern printed on the underside of the perforatedfilm. In other embodiments having electrode traces 36 a, 36 b printed onthe backsheet 34, as depicted, the holes or perforations of the film arelocated so as not to overlie any portions of the electrode traces 36 a,36 b.

In some embodiments, the fluid filter layer 28 includes an adhesivematerial applied to a bottom of the absorbent core 26 or to the topsurface of the backsheet 34. In some embodiments, such as the embodimentshown in FIGS. 2 and 3, the adhesive material may be applied to thebottom of the absorbent core or to the backsheet so as to match ageometry or pattern of the first and/or second electrode traces 36 a, 36b thereby covering the respective first and/or second electrode traces36 a, 36 b. Thus, in FIGS. 2 and 3, a fluid filter layer 28 a, 28 b isprovided above both of electrode traces 36 a, 36 b but in alternativeembodiments, only one or the other of fluid filter layers 28 a, 28 b isprovided above the respective electrode trace 36 a, 36 b.

The adhesive material of fluid filter layer 28 a, 28 b may include a hotmelt adhesive. In some contemplated embodiments, the adhesive materialis either spray coated or slot coated on the bottom of the absorbentcore or on the top of the backsheet after electrodes 36 a, 36 b areprinted thereon. In other embodiments, fluid filter layer 28 a, 28 b ismade of an adhesive film. In some embodiments, electrodes 36 a, 36 bhave a width of about 1 mm to about 3 mm and the adhesive of layer 28 a,28 b has a width about 3 mm to about 25 mm. It is contemplated that thewidth of adhesive of layer 28 a, 28 b is wider than the respectiveelectrodes 36 a, 36 b so as to overhand both sides of electrodes 36 a,36 b. A shim of a slot coater used to apply the adhesive in someembodiments has slots that define the width of adhesive layer 28 a, 28b.

In some embodiments, the fluid filter layer 28 includes a hydrophobiccoating applied to the absorbent core 26. The hydrophobic coating may beapplied in one or more of the following patterns: dots, stripes, orrandom pattern. The hydrophobic coating may be sprayed onto theabsorbent core 26 or applied as an adhesive film, for example.

In some embodiments, the fluid filter layer 28 or the fluid filter layer28 a, 28 b includes a soluble coating applied over the first and secondelectrode traces 36 a, 36 b. For example, the soluble coating mayinclude a water soluble coating and/or a urine soluble coating. In someembodiments, the soluble coating includes a dissolvable ink. The solublecoating is absent from portions of the first and second electrode traces36 a, 36 b at which the electrical contacts of the passive RFID tag 30couple to the first and second electrode traces 36 a, 36 b.

In some embodiments, the fluid filter layer 28 includes a cellulosicnonwoven material. For example, the cellulosic nonwoven material mayinclude tissue paper. Thus, the cellulosic nonwoven material is akin toa coffee filter, for example.

In the illustrative examples of FIGS. 1-3, the fluid filter layer 28 orthe fluid filter layer 28 a, 28 b, as the case may be, is locatedbeneath the absorbent core 26. However, it is contemplated by thisdisclosure that, in some embodiments, the fluid filter layer 28 or fluidfilter layer 28 a, 28 b is situated above the absorbent core 26. In suchembodiments, the fluid filter layer 28 or fluid filter layer 28 a, 28 balso may be situated above the topsheet 22. Alternatively, the fluidfilter layer 28 or the fluid filter layer 28 a, 28 b may be situatedbeneath the topsheet 22 so as to be sandwiched between the topsheet 22and absorbent core 26, either above or below adhesive layer 24.

In the illustrative example of FIG. 1, each of elements 22, 24, 26, 28,32, and 34 of the incontinence detection pad 20 is rectangular in shape.Also in the illustrative example of FIG. 1, an outer periphery 38 of thefluid filter layer 28 is coextensive with an outer periphery 40 of theabsorbent core 26. Peripheries 38, 40 are also coextensive with an outerperiphery 42 of adhesive layer 24 in the illustrative embodiment. Inother embodiments, fluid filter layer 28 is larger than depicted so thatits outer periphery 38 is coextensive with an outer periphery 44 of thetopsheet 22. In such embodiments, periphery 38 of the fluid filter layer28 is also coextensive with an outer periphery 46 of the backsheet 34.Optionally, the fluid filter layer 28 may be laminated to the absorbentcore 26 using one or more of the following: adhesive, heat bonding, orlatex bonding.

In some embodiments, the fluid filter layer 28 or the fluid filter layer28 a, 28 b may include an adhesive with desiccant media. The adhesivewith desiccant media may adhere the topsheet to the absorbent core, forexample. A suitable adhesive in this regard may be the FULLCARE™adhesive available from H. B. Fuller Company of St. Paul, Minn.Alternatively or additionally, the fluid filter layer 28 or the fluidfilter layer 28 a, 28 b may include a desiccant. For example, thedesiccant may be sprayed onto the topsheet 22 or the absorbent core 26or the backsheet 34.

As will be discussed in further detail below in connection with FIGS.10-12, the adhesive of the fluid filter layer 28 or fluid filter layer28 a, 28 b also may be applied so as to cover a sacrificial electrodetrace portion 36 c that is located above the backsheet 34 in spacedapart relation with the first and second electrodes 36 a, 36 b. Theadhesive also may be applied to portions 36 a′, 36 b′ of the first andsecond electrode traces 36 a-36 b that may extend beyond a periphery ofthe absorbent core.

Referring now to FIGS. 4A-4D, prior to assembly of the passive RFID tag30 onto backsheet 34 so as to electrically couple to traces 36 a, 36 b,tag 30 is situated on a release liner sheet 48. As shown in FIG. 4B, anillustrative embodiment of the passive RFID tag 30 includes, from top tobottom, a foam spacer 50, a foam-to-tag adhesive layer 52, a conductiveadhesive layer 54, an inlay film 56, an inlay antenna 58, and anon-conductive adhesive 60. As also shown in FIG. 4B, the release liner48 is situated beneath inlay antenna 58 and non-conductive adhesive 60.In the illustrative embodiment, release liner 48 comprises a Model No.17782 L-10 Easy Release Polyethylene Terephthalate (PET) Liner availablefrom Technicote, Inc. of Miamisburg, Ohio. The foam spacer 50 of theillustrative embodiment comprises a Model No. 4 mm Volara 2A XLPE Foamavailable from Sekisui Voltek, LLC of Coldwater, Mich. The foam-to-tagadhesive 52 and the non-conductive adhesive 60 each comprises0.0035″L1+DCP adhesive available from 3M of St. Paul, Minn. Theconductive adhesive comprises 55 μm 9750 adhesive also available from3M. Inlay film 56 comprises 50 μm PET film. Inlay antenna 58 comprises 9μm aluminum.

In FIG. 4C, the foam layer 50 and foam-to-tag adhesive 52 is removed toexpose the inlay antenna 58 which includes a first embodiment ofelectrode-to-tamper-input leads 62 a, 62 b. In FIG. 4D three passiveRFID tags 30 on the sheet of underlying release liner 48 can be seen.The tags 30 are provided on a roll of release liner 48 which is unrolledduring the manufacturing process of incontinence detection pads 20. RFIDtags 30 and release liner 48 shown in FIGS. 4A-4D are substantiallysimilar to those shown in FIGS. 57 and 58 of International PublicationNo. WO 2017/087452 A1 and described at paragraphs 336-338 thereof. Asnoted above International Publication No. WO 2017/087452 A1 isincorporated by reference herein.

Referring now to FIGS. 5A-5D, additional details of one alternativeembodiment of an antenna inlay 58 contemplated herein is shown. It hasbeen found that, when RFID tags 30 having antenna inlays 58 like thatshown in FIGS. 4A-4C are used, the electromagnetic filed generated fromthe transmit antenna that powers the RFID tag 30 may induce a current inthe tamper input leads 62 a, 62 b which results in the RFID chip of tag30 making a false positive reading. That is, the RFID chip sets a tamperbit indicating that the incontinence detection pad 20 is wet when, infact, it is not wet. Thus, according to the present disclosure, one ormore current limiting resistors are provided on the antenna inlay 58 toprevent or reduce the false positives produced by the electromagneticfield emitted by the transmit antenna of an associated reader.

As shown in FIG. 5A, release liner or film layer 48 carries ten antennainlays 58 made of aluminum prior to installation in the respective RFIDtags 30. One of the antenna inlays 58 of the embodiment of FIGS. 5A-5Dis shown in FIG. 5B. Inlay 58 includes a pair of large antenna patches64, a first undulated trace 66 interconnecting patches 64, a firstelectrical contact 68, a second electrical contact 70, a secondundulated trace 72 extending from contact 68 toward contact 70, and athird undulated trace 74 extending from contact 70 toward contact 68.Tamper input leads 62 a, 62 b extend from respective undulated traces72, 74 toward undulated trace 66 in spaced parallel relation with eachother. Thus, lead 62 a, contact 68, and undulated trace 72 form one ofthe tamper inputs to the RFID chip and lead 62 b, contact 70, andundulated trace 74 form the other of the tamper inputs to the RFID chip.

The RFID chip of tag 30 is very small and electrically couples to traceleads 62 a, 62 b and to antenna patches 64. Suitable RFID chips for usein RFID tags 30 include model nos. G2iL+(SL3S1213FUF or SL3S1213FUD/BG)chips available from NXP Semiconductors N.V. of Eindhoven, Netherlands.In the illustrative example, antenna patches 64 are mirror images ofeach other and the tamper inputs (one of which comprises elements 62 a,68, 72 and the other of which comprises elements 62 b, 70, 74) aremirror images of each other. Elements 62 a, 68, 72 and elements 62 b,70, 74 are sometimes referred to herein as electrical contact portionsof antenna inlay 58.

As compared to prior art antenna inlays, such as those disclosed in FIG.57 and described in paragraphs 336-337 of International Publication No.WO 2017/087452 A1 which is already incorporated by reference herein,antenna inlays 58 of the embodiment of FIGS. 5A-5D herein have a gap 76formed in each lead 62 a, 62 b, thereby separating first lead 62 a intoa first lead segment 62 a′ and a second lead segment 62 a″ andseparating second lead 62 b into a third lead segment 64 a′ and a fourthlead segment 64 b″ as shown in FIGS. 5C and 5D. In the illustrativeexample, first and second resistors 78 are attached to leads 62 a, 62 bsuch that the first resistor 78 spans the gap 76 of lead 62 a therebyelectrically coupling lead segment 62 a′ with lead segment 62 a″ andsuch that the second resistor 78 spans the gap 76 of lead 62 b therebyelectrically coupling lead segment 62 b′ with lead segment 62 b″. Thus,in connection with the embodiment of FIGS. 5A-5D, resistors 78 are thecurrent limiting resistors mentioned above. In some embodiments, thefirst and second resistors 78 both have resistance values of about 2.4MΩ. Suitable resistors 78 in this regard include model no.RC0402FR-0724L 2.4 MΩ resistors available from Yageo Corporation of NewTaipei City, Taiwan. In other embodiments, however, resistors 78 haveresistance values from about 1 MΩ to about 2.5 MΩ.

Referring now to FIGS. 6A-6C, another alternative embodiment antennainlay 58 is shown. Antenna inlay 58 of the FIG. 6A-6C embodiment issubstantially the same as antenna inlay 58 of the FIG. 5A-5D embodimentexcept that the location of gaps 76 are different and first and secondresistors 80, 82 are used in lieu of resistors 78. Otherwise, the samereference numbers are used in the FIGS. 5A-5D embodiment and the FIGS.6A-6C embodiment to denote like components. With reference to theorientation of antenna inlay 58 in FIGS. 6A-6C, gaps 76 are provided inhorizontal portions of leads 62 a, 62 b rather than in vertical portionsas was the case with the FIGS. 5A-5D embodiment. The location of gaps 76is shown best in FIG. 6B in this regard. Leads 62 a, 62 b are upsidedown L-shaped in the illustrative examples.

The resistance values of resistors 80, 82 are different from each otherin some embodiments. In the illustrative example of FIGS. 6A-6C,resistor 80 is a model no. AC0402FR-072ML 2-Mega Ohms 0402 resistoravailable from Yageo Corporation of New Taipei City, Taiwan and resistor82 is a model no. RC0402JR-070RL 0-Ohms 0402 resistor also availablefrom Yageo Corporation. Thus, resistor 80 has a resistance of 2 MΩ andresistor 82 has a resistance of 0Ω in the illustrative embodiment. Inother embodiments, resistors 80, 82 may have resistance values fromabout 1 MΩ to about 2.5 MΩ. Thus, according to the present disclosure,only one resistor may be used with antenna inlay 58 to span therespective gap 76 in either lead 62 a or lead 62 b, as the case may be.In such embodiments, one of leads 62 a, 62 b may be formed as acontinuous lead without any gap 76.

Referring now to FIGS. 7A-7C, yet another alternative embodiment antennainlay 58 is shown. Antenna inlay 58 of the FIG. 7A-7C embodiment issubstantially the same as antenna inlay 58 of the FIG. 5A-5D embodimentexcept that the location of gaps 76 are different and resistors 84 areused in lieu of resistors 78. Otherwise, the same reference numbers areused in the FIGS. 5A-5D embodiment and the FIG. 7A-7C embodiment todenote like components. With reference to the orientation of antennainlay 58 in FIGS. 7A-7C, gaps 76 are provided in vertical portions ofleads 62 a, 62 b but are located further upwardly than the gaps 76 ofthe FIGS. 5A-5D embodiment. The location of gaps 76 is shown best inFIG. 7B in this regard.

The resistance values of both resistors 84 are the same in someembodiments. In the illustrative example of FIGS. 7A-7C, resistor 84 isa model no. ERJ2LW/2BW 0402 resistor available from PanasonicCorporation of Osaka, Japan. Thus, resistors 84 have resistances of 10MΩ in the illustrative example. In other embodiments, resistors 84 mayhave resistance values from about 1 MΩ to about 2.5 MΩ. As should beapparent from the embodiments of FIGS. 5A-5D, 6A-6C and 7A-7C, gaps 76and the respective resistors may be located anywhere along leads 62 a,62 b according to the present disclosure.

Referring now to FIG. 7D, yet another alternative embodiment of aportion of antenna inlay 58 is shown. Antenna inlay 58 of the FIG. 7Dembodiment is substantially the same as antenna inlay 58 of the FIG.7A-7C embodiment except that the location of gaps 76 are different andresistors 85, 87 are used in lieu of resistor 84. Otherwise, the samereference numbers are used in the FIGS. 7A-7C embodiment and the FIG. 7Dembodiment to denote like components. With reference to the orientationof antenna inlay 58 in FIG. 7D, gaps 76 are provided in verticalportions of leads 62 a, 62 b but are located further upwardly than thegaps 76 of the FIGS. 7A-7C embodiment. Also, in the FIG. 7D embodiment,extensions 89 are included in trace portions 62 a′, 62 a″, 62 b′, 62 b″to provided widened portions of traces 62 a, 62 b above and below therespective gaps 76. The extensions 89 provide a larger contact area forthe electrical contacts of resistors 85, 87 than the embodiments ofFIGS. 5A-5D, 6A-6C, and 7A-7C. The extensions 89 of trace portions 62a′, 62 a″ extend in an opposite direction than the extensions 89 oftrace portions 62 b′, 62 b″. More particular, in the orientation of FIG.7D, extensions 89 associated with trace portions 62 a′, 62 a″ extend tothe left and extensions 89 associated with trace portions 62 b′, 62 b″extend to the right.

The resistance value of resistor 85 is different than the resistancevalue of resistor 87 in some embodiments. In the illustrative example ofFIG. 7D, resistor 85 is a 2.4 MΩ resistor and resistor 87 is a 1 MΩresistor. Suitable resistors 85 include the model no. RC0402FR-072M4Lresistor available from Yageo Corporation of New Taipei City, Taiwan;the model no. RK73H1ETTP2404F resistor available from KOA Corporation ofNagano, Japan; the model no. CRCW04022M40FKED resistor available fromVishay Intertechnology Inc. of Malvern, Pa.; and the model no.CR0402F2M4Q10 resistor available from Ever Ohms Technology Co. Ltd. ofKaohsiung City, Taiwan. Suitable resistors 87 include the model no.RC0402FR-071ML 1 MΩ resistor available from Yageo.

The RFID chips used in RFID tags 30 are configured such that sensedresistances between the tamper inputs 62 a, 62 b that are about 5 MΩ toabout 6 MΩ or less indicate that moisture is present on the incontinencedetection pad 20 and is of sufficient volume to be considered anincontinence event. The RFID chips used in RFID tags 30 are alsoconfigured such that sensed resistances between the tamper inputs 62 a,62 b that are about 20 MΩ or more indicates that the incontinencedetection pad 20 is considered to be dry. In between these twothresholds is a gray area in which it is uncertain whether the pad 20 iswet or dry. From an alerting standpoint, the pad 20 is still consideredto be dry in some embodiments when the resistance between the tamperinputs 62 a, 62 b is in the gray area between the lower (wet) and upper(dry) resistance thresholds.

The resistors 78, 80, 82, 84, 85, 87 provide isolation for the tamperinput pins of the RFID chip connected to leads 62 a, 62 b from RF energycoupling caused by (a) the proximity of the tamper input lines 62 a, 62b to the antenna patches 64 powering the RFID chip of tag 30, and/or (b)the effect of the conductive detection grid (aka electrode traces 36 a,36 b) being connected to the tamper inputs. It is also contemplated bythis disclosure that a single resistor could be used on a particularinput of the RFID chip, such as either on the VDD pin or the Out pin,and achieve the desired isolation from the RF energy. Alternatively,resistors on both of these pins may be used in some embodiments.

Referring now to FIG. 8, two alternative embodiment antenna inlays 58 onthe respective release film 48 each have a sacrificial connectingportion 86 that interconnects the tamper input leads 62 a, 62 b. TheRFID integrated circuit chip has electrical contacts or pins thatelectrically couple to the leads 62 a, 62 b of the first antenna inlay(i.e., the upper antenna inlay 58 in FIG. 8) when the RFID integratedcircuit chip is attached to the backsheet 48. According to thisdisclosure, the operation of the RFID chip is tested to confirm that thetamper inputs of the RFID chip, which are coupled to leads 62 a, 62 b,properly indicate a short circuit prior to installation of theassociated RFID tag 30 into an incontinence detection pad 20.

After the RFID chip is attached to the leading inlay 58, energy isemitted to provide the RFID integrated circuit chip with power via theantenna patches 64 of the first antenna inlay 58. A return signal isoutput by the RFID integrated circuit chip and is transmitted via theantenna patches 64 of the first antenna inlay 58 to the testingequipment which is similar to the readers disclosed in InternationalPublication No. WO 2017/087452 A1 and U.S. application Ser. No.15/596,036 which are already incorporated by reference herein. Seeparticularly FIGS. 29A-29C of International Publication No. WO2017/087452 A1 and the related description as well as FIG. 8 of U.S.application Ser. No. 15/596,036 and the related description.

After receiving the return signal, the testing equipment processes thereturn signal from the RFID integrated circuit chip to confirm that theRFID integrated circuit chip is working properly due to the returnsignal indicating that the tamper inputs and the respective sacrificialconnection portion of the first antenna inlay 58 form a completed shortcircuit. After the return signal is processed to determine whether theRFID chip passed or failed the test, the release liner 48 is cut at alocation indicated by dotted line 88 a in FIG. 8. Cutting release liner48 along dotted line 88 a severs at least a part of the sacrificialconnecting portion 86 from the pair of leads 62 a, 62 b of the firstantenna inlay 58 to place the leads 62 a, 62 b of the first antennainlay 58 in an open circuit configuration and leaving another part ofthe sacrificial connecting portion 86 behind on a portion of the releaseliner 48 that is associated with a neighboring antenna inlay 58 (i.e.,the antenna inlay 58 at the bottom of FIG. 8). Release liner 48 issometimes referred to as a “backsheet” herein, even though it is adifferent element than backsheet 34 of incontinence detection pad 20.Any antenna inlay/RFID chip combinations that fail the test arediscarded as scrap. Those that pass the test continue on with themanufacturing process to ultimately be installed on the backsheet 34 ofthe respective incontinence detection pad 20.

According to the testing procedure just described, each antenna inlay 58has the sacrificial short 86 formed with the tamper input contact leads62 a, 62 b so that a test for proper functioning of an RFID chip of thepassive RFID tag 30 can be undertaken during manufacture prior tosevering of the sacrificial short. In FIG. 8, a cut line 88 b isillustrated in connection with the neighboring antenna inlay 58. Itshould be understood that third, fourth, fifth and so on antenna inlays58 follow the antenna inlay 58 beneath the cut line 88 b such that thetesting operation is carried out in series for each of the antennainlay/RFID chip combinations. In the illustrative example, thesacrificial connection portions 86 are U-shaped with fairly sharpcorners between the vertical and horizontal segments (as viewed in theorientation of FIG. 8). In other embodiments, the sacrificial connectionportions 86 may have rounded U-shapes, V-shapes or any other shape thatinterconnects leads 62 a, 62 b and passes through the respective cutline, such as illustrative cut lines 88 a, 88 b.

Referring now to FIG. 9A, an alternative embodiment backsheet 134 isshown having a different geometry or pattern of first and secondelectrode traces 136 a, 136 b as compared to the electrode traces 36 a,36 b of the backsheet 34 shown in FIGS. 1-3. One of the differences isthat trace 136 a includes a semicircular trace portion 138 having aradius of about 201.5 mm in the illustrative example. Trace 136 a alsoincludes an arcuate trace portion 140 having a radius of about 321.8 mmin the illustrative example. The arcuate trace portion 140 interconnectswith one end of the semicircular trace portion 138. Portions 138, 140are in opposite directions. Another difference is that sacrificial traceportion 136 b′ extends at an angle, illustratively 40°, with respect toa long dimension of backsheet 134, whereas portion 36 b′ on backsheet 34is oriented parallel with the long dimension of backsheet 34. Otheraspects of the patterns of traces 136 a, 136 b on backsheet can bereadily gleaned from a visual inspection of FIG. 9A. Backsheet 134 alsohas registration marks 141 a, 141 b that are used during the manufactureof the incontinence detection pad 20 in which backsheet 134 is included.

Still referring to FIG. 9A, the overall length of backsheet 134, andtherefore the overall length of the associated pad 20, is about 900 mmand the overall width of backsheet 134, and therefore the overall widthof the associated pad 20, is about 750 mm in the illustrativeembodiment. Absorbent core 26 is generally centered on backsheet 134 hasas a length of about 790 mm and a width of about 660 mm (see the dottedline rectangle in FIG. 9A which represents the footprint of absorbentcore 26). Furthermore, angle 900 is about 40 degrees in the illustrativeembodiment and angle 902 is about 45 degrees in the illustrativeembodiment. Portion 138 of trace 136 a has a radius of about 201.5 mmand portion 140 has a radius of about 321.8 mm in the illustrativeembodiment as noted above. Also in the illustrative embodiment, portion139 of trace 136 b has a radius of about 201.5 mm and portion 143 oftrace 136 b has a radius of about 351.5 mm.

Additional dimensions of illustrative backsheet 134 include thefollowing: dimension 904 is about 647.0 mm, dimension 906 is about 443.5mm, dimension 908 is about 167.8 mm, dimension 910 is about 83.5 mm,dimension 912 is about 127.2 mm, dimension 913 is about 85.5 mm,dimension 914 is about 277.0 mm, dimension 916 is about 110.0 mm,dimension 918 is about 127.0 mm, dimension 920 is about 165 mm, anddimension 922 is about 83.5 mm. It should be appreciated that there is atolerance range associated with each of the given dimensions. Suchtolerance ranges include ranges as high as about +/−4.0 mm and as low asabout +/−0.1 mm for the various dimensions and there is also a tolerancerange of about +/−0.5 degrees for the angles.

The dimensions given for the illustrative example of FIG. 9A areprovided for purposes of comparison such as, for example, dimension 914is at least twice that of dimension 912 or dimension 918. Also,dimension 914 is at least three times that of dimension 910 or dimension922. Many other similar comparisons can be made based on each of thegiven dimensions associated with pad 134 such that each possiblecomparison is contemplated herein. In the illustrative example,dimension 904 is generally centered along the overall length ofbacksheet 134. Other information concerning the illustrative backsheet134, including other dimensions, can be found in FIG. 9A of U.S.Provisional Patent Application No. 62/551,565 which was filed Aug. 29,2017 and which is hereby incorporated by reference herein.

Referring now to FIG. 9B, backsheet 134 includes, from top to bottom,carbon conductive ink 142, a breathable low density polyethylene (LDPE)film 144, a layer of hot melt adhesive 146, and a layer of polypropylene(PP) spunbond nonwoven material 148. An enlarged view of a portion ofFIG. 9A is shown in FIG. 9C and depicts a tag footprint 150 indicating alocation at which the passive RFID tag 30 is attached to the electrodes136 a, 136 b of the backsheet 134.

Referring now to FIG. 10, backsheet 134 is shown with a fluid barrierlayer 90 of adhesive applied over first and second portions 136 a′, 136b′ of respective first and second electrode traces 136 a, 136 b in aregion of the backsheet 134 located substantially outboard of aperiphery of an absorbent core (not shown, but substantially the same asabsorbent core 26 of FIGS. 1 and 2), the periphery being represented bya dotted rectangle 140 in FIG. 10. The adhesive of barrier layer 90comprises an extra amount of adhesive as compared to the other portionsof the layer of peripheral hot melt adhesive 32 shown in FIGS. 1 and 2,for example. Barrier layer 90 prevents low volumes (or really, anyvolumes) of moisture from electrically bridging across trace portions136 a′, 136 b′ outboard of periphery 140 which is devoid of anyabsorbent core material.

Portions 136 a′, 136 b′ exist outboard of periphery 140 as a result ofthe sacrificial trace portion 136 c which was once attached to portions136 a′, 136 b′ prior to the preceding backsheet 134 being severed fromthe illustrative backsheet of FIG. 10 during a manufacturing and testingprocess of the type described in paragraphs 328-332 in connection withFIG. 36 of International Publication No. WO 2017/087452 A1 which isalready incorporated by reference herein. Due to the speed of themanufacturing process, the precise location at which backsheets 134 aresevered from each other may vary over time or frombacksheet-to-backsheet. Thus, barrier layer 90 is applied to adjacentbacksheets 134 so as to assure coverage of trace portions 136 a′, 136 b′regardless of the location at which the backsheets are severed.Accordingly, a small amount of barrier layer 90, on the order of about10 mm to about 30 mm, extends inboard of periphery 140 in theillustrative embodiment.

As shown in FIG. 10, barrier layer 90 includes zones A and C from amongzones A, B and C. The intermediate zone B has an amount of adhesivecoverage that is substantially the same as the rest of peripheraladhesive 32. Thus, zone B, technically, is not considered to part of thebarrier layer 90. In reality and as will be described in further detailbelow in connection with FIG. 12, a slot coating process is used toapply the adhesive of barrier layer 90 simultaneously with theapplication of adhesive of the laterally extending portions ofperipheral adhesive 32.

Referring now to FIG. 11, barrier layer 90 is shown on backsheet 34. Thedescription above of FIG. 10 is, therefore, equally applicable to FIG.11 except where noted below. That is, fluid barrier layer 90 onbacksheet 34 is provided for the same purpose and in substantially thesame manner as provided on backsheet 134. The main difference is thattrace portion 36 b′ of backsheet 34 is parallel with the long dimensionof backsheet 34 rather than being angled as was the case with backsheet134. As a result, zone A of barrier layer 90 of backsheet 34 does notneed to be as wide as zone A of barrier layer 90 of backsheet 134. Insome embodiment, zones A and C of backsheet 34 and zone C of backsheet134 are about 3 mm to about 25 mm in width. Zone A of backsheet 134 ison the order of about 75 mm to about 100 mm in width.

Referring now to FIG. 12, a portion of a slot coater shim 92 having afirst set of openings 94 of narrow width and a second opening 96 havinga width that is wider than the narrow width 94. In some embodiments,openings 94 are sized so that stripes of adhesive or glue 98 have awidth of about 1 mm and opening 96 is sized to that a strip of glue oradhesive 100 has a width of about 3 mm to about 25 mm. Opening 96 is inregistry with portion 36 a′ of respective electrode trace 36 a, orportion 136 a′ of respective electrode trace 136 a, as the case may be.Thus, stripe of glue 100 covers electrode trace portions 36 a′, 136 a′.In the illustrative embodiment, trace portions 36 a′, 136 a′ arecentered within stripe of glue 100. It should be understood that, inconnection with angled trace portion 136 b′, slot coater shim 92 hasanother opening (not shown) that is wider than opening 96 but otherwisesubstantially similar to opening 96. The wider opening is configured sothat a stripe of glue or adhesive having a width of about 75 mm to about100 mm is provided on backsheet 134 over trace portion 136 b′. In thecase of trace portion 36 b′, slot coater shim 92 includes another slot96 in registry with trace portion 36 b′. In an alternative embodiment,slot coater shim 92 as a single large opening that results in barrierlayer 90 spanning the entirety of zones A, B and C shown in FIGS. 10 and11.

Referring now to FIGS. 14A-18, several examples of different alternativegeometries at the end regions of traces 136 a, 136 b of incontinencedetection pad 20 are shown. These same geometries may just as well beincluded in the incontinence detection pad 20 having traces 36 a, 36 b.In some contemplated embodiments, backsheet 34 and backsheet 134 eachinclude a thin, flexible, stretchable, polyethylene film laminated to apolypropylene spunbond nonwoven material. In such embodiments, the RFIDtag 30 has a substrate that includes a thin, yet rigid polyethyleneterephthalate (PET) film adhered to the backsheet 34, 134 using adouble-sided conductive nonwoven scrim adhesive.

When adhered together and stretched, the printed PE film backsheet 34,134 can stretch while the PET of the RFID tag 30 does not. Due to thisdisparity in tensile properties, conductive trace breaks have beenobserved at the intersection point of the printed trace and RFID tag 30in the embodiments of backsheets 34, 134 like those shown in FIGS. 10and 11 because RFID tag 30 completely overlaps the respective traces 36a, 36 b, 136 a, 136 b such that opposite ends 152 of RFID tag 30 eachlie outboard of the respective portion of trace 36 a, 36 b, 136 a, 136 bto which it is coupled. Such breaks at the intersection between RFID tag30 and traces 36 a, 36 b, 136 a, 136 b typically results in a loss ofone or more legs (e.g., portions of traces 36 a, 36 b, 136 a, 136 bbeyond the break and spaced from the RFID tag 30) of the circuit,reducing the ability of pad 20 to detect incontinence in the respectivebroken leg segment.

The alternative trace geometries at the end regions of traces 136 a, 136b shown in FIGS. 14A-18 are improved printed trace designs that resultin redundant (e.g., 4 to 5, or even more in some embodiments) contactpoints to the RFID tag 30 on each side, per electrode 136 a, 136 b, asopposed to the designs of FIGS. 10 and 11 which have single contactpoints. Thus, there are multiple electrical pathways to the RFID tag 30from the main portions of traces 136 a, 136 b that lead up to the endregion geometries. The main portions of traces 136 a, 136 b areconsidered to be all portions of traces 136 a, 138 that are not part ofthe redundancy means of the traces 136 a, 136 b. Such end regiongeometries of traces 136 a, 136 b shown in FIGS. 14A-18 are within thescope of the term “redundancy means” as used in the claims of thepresent application. These disclosed geometries of FIGS. 14A-18 improvethe robustness of the pad 20 under severe stress such as may occurduring patient repositioning or other handling.

Referring now to FIGS. 14A-14C, the first and second electrode traces136 a, 136 b each includes a redundancy means 160 for coupling to theelectrical contacts 162 of the passive RFID tag 30 to provide redundantelectrical pathways between the first and second electrode traces 136 a,136 b and the electrical contacts 162. Redundancy means 160 of FIGS.14A-14C comprise portions of the first and second traces 136 a, 136 bthat each has a ladder geometry. The ladder geometry of each of thefirst and second traces 136 a, 136 b includes first and second elongatedsides 164, 166 and a series of rungs 168 a-168 h that interconnects therespective elongated sides 164, 166. At the upper ends of redundancymeans 160, as oriented in FIGS. 14A-14C, each of the elongated sides164, 166 merges into the respective main portion of correspondingelectrode traces 136 a, 136 b as the case may be.

All of the rungs 168 a-168 h of redundancy means 160 are substantiallyperpendicular to the elongated sides 164, 166 in the illustrativeembodiment of FIG. 14A-14C. In other embodiments, some or all of therungs are not perpendicular to the elongated sides 164, 166 such thatthe rungs each extend between the elongated sides at an inclined angleas shown in FIG. 14D, for example, in which three exemplary rungs 168a′, 168 b′, 168 c′ are shown at an inclined angle on a portion of analternative redundancy means 160′ at the end region of electrode 136 b.The other rungs (not shown) of the redundancy means 160′ of FIG. 14D aresimilarly inclined.

In the illustrative example, a width 170 of the main portions of traces136 a, 136 b is about 3 mm. Elongated sides 164, 166 of laddergeometries 160 have the same width 170 of about 3 mm as main portions oftraces 136 a, 136 b in some embodiments. Further illustratively, a width172 of each rung 168 a-168 h is about 2.6 mm. A spacing 174 between abottom of any particular rung 168 a-168 f and a bottom of the nextadjacent rung 168 b-168 g therebelow is about 19.5 mm in theillustrative example. This same spacing 174 is about 19.5 mm if measuredbetween centers of the rungs or from tops of the rungs. The spacingbetween like portions (e.g., bottoms or tops or centers) of rungs 168 gand 168 h is less than 19.5 in the illustrative example.

A spacing 176 between an inner edge of elongated side 164 and an inneredge of the associated elongated side 166 is about 7.0 mm in theillustrative embodiment. Thus, a spacing 178 between an outer edge ofelongated side 164 and an outer edge of the associated elongated side166 is about 13.0 mm in the illustrative example (i.e., 3 mm width 170of elongated side 164+7.0 mm spacing 176 in the gap between sides 164,166+3 mm width 170 of elongated side 166+/− the various tolerances aboveor below these dimensions). Thus, spacing 178 is at least three timeswidth 170 of portions of the first and second traces 136 a, 136 b thatare spaced from the ladder geometries 160. In fact in the illustrativeexample, spacing 178 of 13.0 mm is more than four times width 170 of 3mm.

A spacing 180, shown in FIG. 14A, between inboard edges of elongatedsides 164, 166 of the redundancy means 160 is about 110.0 mm in theillustrative example. The inboard edges of sides 164, 166 are consideredto be the sides closest to the center of RFID tag 30. The spacingbetween opposite ends 152 of RFID tag 30 is about 120 mm. Thus, oppositeend regions of the passive RFID tag 30 each overlie respective portionsof one of the elongated sides 164, 166 of each of the pair of elongatedsides 164, 166 of each ladder geometry 160. In the orientation shown inFIGS. 14A-14C, the left end region of tag 30 overlies a portion ofelongated side 166 of the left hand ladder geometry 160 and the rightend region of tag 30 overlies a portion of elongated side 164 of theright hand ladder geometry 160. Such an arrangement result in the otherelongated sides 164, 166 of the pair of elongated sides 164, 166 of eachladder geometry 160 being situated outboard of the respective end 52 ofthe passive RFID tag 30. More particularly in the orientation shown inFIGS. 14A-14C, elongated side 164 of the left hand ladder geometry 160is outboard of the left end 152 of tag 30 and elongated side 166 of theright hand ladder geometry 160 is outboard of the right end 52 of tag30. By placing tag 30 relative to ladder geometries 160 in this manner,the electrical contacts 162 of tag 30 each overlie a respective one ofelongated sides 164, 166.

In FIG. 14A, tag 30 is situated about midway between the top and bottomof the redundancy means 160. In FIG. 14B, tag 30 is situated close tothe very top of the redundancy means 160. In FIG. 14C, tag 30 issituated at the bottom of the redundancy means. Thus, the laddergeometries 160 have an overall length that is at least three times awidth 182 of RFID tag 30. In the illustrative example, width 182 isabout 42 mm and therefore, the overall length of ladder geometries 160is at least about 126 mm. In the illustrative example, ladder geometriesare about 150 mm in length. To provide a visual indication of where tag30 should be placed in its preferred position midway between the top andbottom of ladder geometries 160, rungs 168 c, 168 e each haveprojections 184 extending outwardly from elongated side 166 of the righthand ladder geometry by about 5.0 mm. Projections 184 serve as first andsecond registration marks that are aligned with respective rungs 168 c,168 e to indicate a mid-region of the length of the ladder geometry 160at which the passive RFID tag 30 is aligned when attached to thesubstrate 134.

When tag 30 is attached to redundancy means 160 about midway between thetop and bottom thereof as shown in FIG. 14A, portions of electricalcontacts 162 of passive RFID tag 30 overlap portions of rungs 168 c, 168d, 168 e on the right side and left side of tag 30, a portion ofelongated side 166 at the left side of tag 30, and a portion ofelongated side 164 at the right side of tag. Thus, there are five pointsof contact between each electrical contact 162 of tag 30 at the left andright sides of tag 30 and redundancy means 160 in the FIG. 14A example.These points of contact are included as part of redundant electricalpaths from the main portions of traces 136 a, 136 b and the electricalcontacts 162 of tag 30. Thus, if a crack or break develops at any ofthese points of contact, there are other electrical paths for current toflow to or from electrical contacts 162 of tag 30 as the case may be.Only if all of the points of contact break between the redundancy means160 and one or the other of electrical contacts 162 will the passiveRFID tag 30 be unable to read a closed circuit resulting from wetnessbridging between traces 136 a, 136 b.

When tag 30 is attached to the top region of the redundancy means 160 asshown in FIG. 14B, portions of electrical contacts 162 of passive RFIDtag 30 overlap portions of rungs 168 a, 168 b on the right side and leftside of tag 30, a portion of elongated side 166 at the left side of tag30, and a portion of elongated side 164 at the right side of tag. Thus,there are four points of contact between each electrical contact 162 oftag 30 at the left and right sides of tag 30 and redundancy means 160 inthe FIG. 14B example. Similarly, when tag 30 is attached to the bottomregion of the redundancy means 160 as shown in FIG. 14C, portions ofelectrical contacts 162 of passive RFID tag 30 overlap portions of rungs168 f, 168 g on the right side and left side of tag 30, a portion ofelongated side 166 at the left side of tag 30, and a portion ofelongated side 164 at the right side of tag. One might consider thebottoms of electrical contacts 162 to be overlapping portions of rungs168 h in addition to or in lieu of overlapping the bottom end ofrespective elongated sides 164, 166, as the case may be. In either case,there are four points of contact between each electrical contact 162 oftag 30 at the left and right sides of tag 30 and redundancy means 160 inthe FIG. 14C example. Thus, there are redundant electrical paths fromthe main portions of traces 136 a, 136 b and the electrical contacts 162of tag 30 in the FIGS. 14B and 14C examples as well.

Referring now to FIG. 14D, an alternative embodiment redundancy means160′ is shown. Redundancy means 160′ is substantially similar toredundancy means 160 and so only a portion of redundancy means 160′ isshown. The description above of redundancy means 160 is equallyapplicable to redundancy means 160′ unless specifically noted otherwise.The difference between redundancy means 160′ and redundancy means 160 isthat the rungs of the ladder geometry are inclined at anon-perpendicular angle to the elongated sides 164, 166. In theillustrative example, rungs 168 a′, 168 b′, 168 c′ are shown but otherrungs of redundancy means 160′ are similarly inclined including thebottom rung in some embodiments. In a variant embodiment, all rungsexcept for the bottom rung are inclined and the bottom rung issubstantially perpendicular to elongated sides 164, 166 like rung 168 hin the embodiment of FIGS. 14A-14C. Also in the illustrative example,angle 188 is about 30 degrees, but angle 188 may be greater or lesserthan 30 degrees (e.g., 5 degrees to 85 degrees or even more or less thanthese numbers) in other embodiments.

In the illustrative example of FIG. 14D, rungs 168 a′, 168 b′ and 168 c′incline upwardly from left elongated side 164 to right elongated side166. It is contemplated that the other rungs of redundancy means 160′are similarly inclined. In a variant embodiment, rungs 168 a′, 168 b′,168 c′, etc. are inclined in the opposite direction. That is, in thevariant embodiment, rungs 168 a′, 168 b′, 168 c′, etc. incline upwardlyfrom right elongated side 166 to left elongated side 164. In stillanother variant, alternating rungs 168 a′, 168 b′, 168 c′, etc. areinclined upwardly and downwardly, one after the other, between elongatedsides 164, 166. FIG. 14D shows the redundancy means 160′ associated withelectrode 136 b. It should be understood that the redundancy means 160′associated with electrode 136 a is similarly shaped.

In still another variant embodiment, shown in FIG. 14E, the rungs of aredundancy means 160″ are formed by a sinusoidal shaped pattern ofconductive material provided in the space between elongated sides 164,166. In FIG. 14E, rungs 168 a″, 168 b″, 168 c″, 168 d″, 168 e″ formed bythe sinusoidal shaped pattern can be seen. Additional rungs are formedin a similar manner. The bottom rung, like rung 168 h of FIGS. 14A-14C,can either be a horizontal segment or a segment of the sinusoidal shapedpattern. FIG. 14E shows the redundancy means 160″ associated withelectrode 136 b. It should be understood that the redundancy means 160″associated with electrode 136 a is similarly shaped.

Referring now to FIG. 14F, another embodiment of a redundancy means 160′is shown. Redundancy means 160′″ is substantially similar to redundancymeans 160 and so the description above of redundancy means 160 isequally applicable to redundancy means 160′″ unless specifically notedotherwise. Redundancy means 160′″ is located at end regions of first andsecond electrode traces 136 a″, 136 b″ which are shown in more detail inFIG. 25 which is discussed below. Like the previous redundancy meansembodiments described herein, redundancy means 160′″ is configured forcoupling to the electrical contacts 162 of the passive RFID tag 30 toprovide redundant electrical pathways between the first and secondelectrode traces 136 a″, 136 b″ and the electrical contacts 162.

Redundancy means 160′″ of FIG. 14F each has a ladder geometry butwithout as many rungs as redundancy means 160. More particularly, laddergeometry of each of the first and second traces 136 a″, 136 b″ includesfirst and second elongated sides 164′, 166′ and a series of rungs 168a-168 f that interconnects the respective elongated sides 164′, 166′.Elongated side 166′ of electrode trace 136 a″ is basically an extensionof the main portion of electrode trace 136 a″ with each rung 168 a-168 fprojecting therefrom to the left in a substantially perpendicular manneras shown in FIG. 14F. Each rung 168 a-168 f of electrode trace 136 a″terminates at the respective elongated side 164′. Similarly, elongatedside 164′ of electrode trace 136 b″ is basically an extensions of themain portion of electrode trace 136 b″ with each rung 168 a-168 fprojecting therefrom to the right in a substantially perpendicularmanner as shown in FIG. 14F. Each rung 168 a-168 f of electrode trace136 b″ terminates at the respective elongated side 166′.

A tag footprint 185 is shown in FIG. 14F (in phantom) to indicate thelocation at which tag 30 is preferably placed when mounted to thesubstrate on which electrodes 136 a″, 136 b″ are printed. The tagfootprint 185 is about 42 mm wide and about 120 mm long to match thedimensions of tag 30. To provide a visual indication of where tag 30should be placed in its preferred position roughly in a central regionbetween the top and bottom of ladder geometries of redundancy means160′″, a pair of projections 184 extend outwardly from elongated side166′ of the right hand ladder geometry by about 5.0 mm. Projections 184serve as first and second registration marks that are slightlymisaligned from respective rungs 168 b, 168 d to indicate a mid-regionof the length of the ladder geometry 160′ at which the passive RFID tag30 should be aligned when attached to the substrate having electrodes136 a″, 136 b″. In the illustrative embodiment of FIG. 14F, a thickness172′ of electrodes 136 a″, 136 b″, elongated sides 164′ 166′, rungs 168a-168 f, and projections 184 is each about 3.0 mm.

Another key difference between redundancy means 160 and redundancy means160′″ is that ladder geometry at the end region of electrode trace 136a″ is offset along its length relative to the ladder geometry at the endregion of electrode trace 136 b″. As is apparent in FIG. 14F, the laddergeometries of traces 136 a″, 136 b″ are parallel to each other and areof substantially equivalent length. In the illustrative example, thespacing between adjacent rungs 168 a-168 f is about 16.5 mm. The offsetbetween the ladder geometries is also about 16.5 mm in the illustrativeexample. Thus, rung 168 a of the ladder geometry of electrode trace 136a″ is generally aligned with rung 168 b of the ladder geometry ofelectrode trace 136 b″ and rung 168 e of the ladder geometry ofelectrode trace 136 a″ is generally aligned with rung 168 f of theladder geometry of electrode trace 136 b″. In other words, the oppositeends of the ladder geometries, defined by rungs 168 a and 168 f, aremisaligned.

Referring now to FIG. 15, redundancy means 190 is shown in which endregions 192 of electrode traces 136 a, 136 b are formed as elongatedsolid conductive ink regions or strips. Opposite ends 162 of passiveRFID tag 30 terminate within the end regions 192 such that portions ofthe end regions 192 extend outwardly beyond the opposite ends 152 of thepassive RFID tag 30. In the illustrative example, the end regions 192 ofthe first and second electrode traces 136 a, 136 b are generallystraight and are each defined along the majority of their length by agenerally straight first side edge 194 and a generally straight secondside edge 196 which is parallel with the first side edge 194. Theopposite ends 152 of the passive RFID tag 30 are also generallystraight. When tag 30 is attached to backsheet 134 having redundancymeans 190, the opposite ends 152 of the passive RFID tag 30 aregenerally parallel with the end regions 192, or more particularly, aregenerally parallel with edges 194, 196 of end regions 192.

In the illustrative example of FIG. 15, the end regions 192 each have alength that is at least three times the width dimension 182 of thepassive RFID tag 30. For example, redundancy means 190 has a length thatis similar to that of redundancy means 160 in some embodiments. Thus,the overall length of end regions 192 is at least about 126 mm and, inthe illustrative example, is about 150 mm in length. Furthermore,dimensions 170, 178, 180 shown in FIG. 15 are substantially the same asthese same dimensions shown in FIG. 14A. Thus, in FIG. 15, dimension 170is about 3 mm, dimension 178 is about 13.0 mm, and dimension 180 isabout 110.0 mm. As noted above, the length dimension of tag 30 betweenopposite ends 152 is about 120.0 mm. Thus, end regions 192 areconfigured so that solid conductive ink is outboard of opposite ends 152of tag 30 when tag 30 is mounted properly to backsheet 134 as shown inFIG. 15. Tag 30 can be mounted closer to a top region or closer to abottom region of redundancy means 190 if desired.

There are practically an unlimited or infinite number of electrical flowpaths between the main portions of electrode traces 136 a, 136 b and theelectrical contacts 162 at the opposite ends 152 of tag 30. Thus, thereare only a couple scenarios at the redundancy means 190 in which thepassive RFID tag 30 will be unable to read a closed circuit resultingfrom wetness bridging between traces 136 a, 136 b. One is if a break orcrack totally severs end regions 190 from edge 194 to edge 196 at alocation between the segments 136 a, 136 b and the respective electricalcontact 162 of tag 30. Another is if a break or crack forms along ornear the complete perimeter of the portion of tag 30 that overlaps oneor the other (or both) of regions 192 of redundancy means 190 at theinterface between electrical contacts 162 and regions 192.

Referring now to FIG. 16, redundancy means 200 is shown in whichportions of the first and second electrode traces 136 a, 136 b are eachconfigured to have a comb pattern. Each comb pattern of the redundancymeans 200 includes an elongated side or spine 202 and a series of teeth204 extending from the respective elongated side 202. If theillustrative embodiment, the teeth 204 of each comb pattern extend insubstantially perpendicular relation with the respective elongated side200. Furthermore, dimensions 170, 178, 180, 182 shown in FIG. 16 aresubstantially the same as these same dimensions shown in FIG. 14A. Thus,in FIG. 16, dimension 170 is about 3 mm, dimension 178 is about 13.0 mm,dimension 180 is about 110.0 mm, and dimension 182 is about 42 mm.

The teeth 204 of the comb pattern of the portion of the first electrodetrace 136 a and the teeth 204 of the comb pattern of the portion of thesecond electrode trace 136 b extend toward each other. In theillustrative embodiment, redundancy means 200 has semicircular troughs206 between teeth 204 in between the locations at which teeth 204 mergewith spine 202. In other embodiments, troughs 206 have a shape otherthan semicircular, such as being square shaped, V-shaped, etc. Oppositeends 152 of the passive RFID tag 30 each may overlie a plurality ofteeth 204 of the respective comb pattern. However, the elongated sides202 of each comb pattern are located outboard of the respective ends 152of the RFID tag 30 as shown in FIG. 16.

In the illustrative embodiment, electrical contacts 162 at the oppositeends 152 of tag 30 each overlap five of teeth 204. Thus, there are fiveelectrical paths from main portions of electrodes 136 a, 136 b to therespective electrical contacts 162 of tag 30 in the illustrative exampleof FIG. 16. If desired, tag 30 can be attached to redundancy means 200closer to the top or bottom thereof and electrical contacts 162 willeach overlap five teeth 204 assuming the tag 30 is not positioned toofar below the bottom-most tooth 204 or too far above the top-most tooth2004. In the illustrative example, each comb pattern of redundancy means200 has a length that is at least three times width dimension 182 of thepassive RFID tag 30.

Referring now FIG. 17, redundancy means 210 is shown in which each ofthe end regions of electrodes 136 a, 136 b are substantially straightand have a series of circular holes 212 that are aligned along thelength of the straight end regions of the redundancy means 210. In theillustrative example of FIG. 17, each end region of redundancy means 210has a first elongated straight edge 214 and a second elongated straightedge 216 and each circular hole 212 is located about midway between thefirst and second elongated straight edges 214, 216 of the respective endregion. Furthermore, dimensions 170, 178, 180, 182 shown in FIG. 17 aresubstantially the same as these same dimensions shown in FIG. 14A. Thus,in FIG. 17, dimension 170 is about 3 mm, dimension 178 is about 13.0 mm,dimension 180 is about 110.0 mm, and dimension 182 is about 42 mm.

Opposite ends 152 of the passive RFID tag 30 each overlie a portion of aplurality of the circular holes 212 of each series of circular holes 212of the respective end region and a portion of each end region isoutboard of the respective end 152 of the passive RFID tag 30. Thus, theconductive ink between the holes 212 over which ends 152 of tag 30 arepositioned are included in redundant electrical paths to electricalcontacts 162 of tag 30. In the illustrative example, ends 152 of tag 30each overlie four holes 212. In the illustrative example, redundancymeans 210 has a length that is at least three times width 182 of tag 30.Thus, tag 30 can be coupled to redundancy means 210 above and below theposition shown in FIG. 17.

Based on the above discussion, it is apparent that redundancy means 160,160′, 210 each include enlarged end regions of electrode traces 136 a,136 b that have a series of holes through the conductive ink forming therespective end region such that the substrate, such as backsheet 134, isexposed through the series of holes. With regard to redundancy means160, 160′, at least some of holes of the series of holes of the endregions are substantially quadrilateral in shape. For example, thesubstantially quadrilateral shape of redundancy means 160 issubstantially rectangular between the adjacent rungs 168 a-168 h. In avariant embodiment, the substantially quadrilateral shape of holes of aredundancy means includes holes that are substantially square. In thecase of redundancy means 160′, the substantially quadrilateral shapebetween the rungs is substantially rhomboid. The term “rhomboid” hereinis intended to cover a rhombus having sides of substantially equallength and rhomboids having sides of unequal length. In the case ofredundancy means 210, the holes 212 of the series of holes 212 are eachsubstantially circular in shape.

By providing redundancy means 160, 160′, 210 with holes along therespective lengths thereof, less conductive ink is used to print therespective redundancy means 160, 160′, 210 as compared to redundancymeans 190 of FIG. 15 which does not include any holes of any shape alongit length. This represents a cost savings for redundancy means 160,160′, 210 as compared to redundancy means 190. However, the tradeoff isthat there are less electrical paths between main portions of electrodetraces 136 a, 136 b and electrical contacts 162 of tag 30 used withredundancy means 160, 160′, 210 as compared to redundancy means 190.

This disclosure also contemplates embodiments of redundancy means havingholes of other shapes. In some such embodiments, each of the end regionsof traces 136 a, 136 b are substantially straight and the series ofholes, of whatever shape, of each end region are aligned with each otheralong the length of the respective end region. For example, each endregions may be substantially straight with each end region having afirst elongated straight edge (e.g., edge 214) and a second elongatedstraight edge (e.g., edge 216) and each hole of the series of holes maybe located about midway between the first and second elongated straightedges of the respective end region. In some embodiments, the end regionsmay be at least three times wider than main portions of the first andsecond electrode traces 136 a, 136 b that are spaced from the endregions. For example, in the illustrative embodiments of redundancymeans 160, 160′, 210, dimension 178 is at least three times dimension170. In fact, in connection with redundancy means 160, 160′, 210, theend regions of electrode traces 136 a, 136 b are at least four timeswider than the main portions of the first and second electrode traces136 a, 136 b that are spaced from the end regions.

Regardless of the shape of the holes provided in the redundancy means,opposite ends 152 of the passive RFID tag 30 each overlie a portion of aplurality of such holes of each series of holes of the respective endregion and a portion of each end region is outboard of the respectiveend 152 of the passive RFID tag 30. In the illustrative examples, theend regions of the first and second electrode traces 136 a, 136 b aregenerally straight and the opposite ends 152 of the passive RFID tag 30are generally straight, such that the opposite ends 152 of the passiveRFID tag 30 are generally parallel with the end regions. In theillustrative examples, the end regions each may have a length that is atleast three times the width dimension 182 of the passive RFID tag 30. Inother embodiments, the end portions are less than three times the width182 of tag 30 or more than four times the width of tag 30.

Referring now to FIG. 18, redundancy means 220 includes portions of thefirst and second traces 136 a, 136 b that are each configured as anelongated loop. Each elongated loop of redundancy means 220 is basicallythe same as the ladder geometry of redundancy means 160 but with rungs168 a-168 g omitted. Thus, similar reference numbers are used in FIG. 18for portions of redundancy means 220 that are substantially the same aslike portions of redundancy means 160 of FIGS. 14A-14C. Illustratively,the elongated loops of redundancy means 220 each include a firstelongated segment 164, a second elongated segment 166 that issubstantially parallel with the first elongated segment 164, and an endsegment 168 h that interconnects lower ends of the first and secondelongated segments 164, 166 in the orientation shown in FIG. 18.

Upper ends of segments 164, 166 of the elongated loops, as oriented inFIG. 18, merge gradually into main portions of electrode traces 136 a,136 b. In the illustrative example, opposite ends 152 of the passiveRFID tag 30 are located over respective spaces between correspondingfirst and second elongated segments 164, 166 of the associated elongatedloop. In the illustrative example, each of the opposite ends 152 of thepassive RFID tag are straight and substantially parallel with the firstand second elongated segments 164, 166 of the elongated loops. In someembodiments, each of the first, second, and end segments 164, 166, 168 hhas a width of a first dimension thereacross and portions of the firstand second electrode traces spaced from the elongated loops also mayhave widths substantially equal to the first dimension thereacross. Thefirst dimension is about 2.6 mm to about 3.0 mm in some embodiments, forexample.

In the illustrative example, the elongated loops of redundancy means 220each have two points of contact with the respective electrical contact162 of tag 30. Specifically, segment 166 has two points of contact withthe left electrical contact 162 of tag 30 and segment 164 has two pointsof contact with the right electrical contact 162 of tag 30, as orientedin FIG. 18. Thus, if the upper portion of segment 166 of the leftelongated loop breaks or cracks, an electrical pathway from the mainportion of electrode 136 b to the left electrical contact 162 of tag 30still exists along segment 164, end segment 168 h, and the bottomportion of segment 166. Similarly, if the upper portion of segment 164of the right elongated loop breaks or cracks, an electrical pathway fromthe main portion of electrode 136 a to the right electrical contact 162of tag 30 still exists along segment 166, end segment 168 h, and thebottom portion of segment 164.

Still referring to FIG. 18, passive RFID tag 30 is coupled to redundancymeans 220 such that upper and lower edges of tag 30 are generallyaligned with registration marks 184 that project outwardly from segment166 of the right loop of redundancy means 220. In the illustrativeexample, the elongated loops each have a length that is at least threetimes width dimension 182 of the passive RFID tag 30. Thus, if desired,tag 30 can be coupled to the elongated loops of redundancy means 220 atpositions above and below the illustrative position shown in FIG. 18.

While redundancy means 220 has only two points of contact with each ofelectrical contacts 162 of tag 30, less conductive ink is need to makethe elongated loops of redundancy means 220 as compared to the othergeometries of redundancy means 160, 160′, 190, 200, 210 which have morepoints of contact with electrical contacts 162 of tag 30. As was thecase with redundancy means 160, 160′, 190, 200, 210 described above,dimensions 170, 178, 180, 182 are also shown in FIG. 18 in connectionwith the discussion of redundancy means 220. Therefore, the discussionabove regarding dimensions 170, 178, 180, 182 and the relativecomparisons between the dimensions is equally applicable to FIG. 18. Itshould also be appreciated that all dimensions mentioned herein,including dimensions 170, 178, 180, 182, are merely examples of suitabledimensions and that other embodiments having dimensions different thanthose specifically mentioned herein are within the scope of the presentdisclosure.

According to the present disclosure, in some embodiments of theincontinence detection pad 20 that includes redundancy means 160, 160′,190, 200, 210, 220, the associated substrate on which the redundancymeans 160, 160′, 190, 200, 210, 220 is provided may comprise thebacksheet 34, 134 which, in turn, may include a first layer of fluidimpermeable material and a second layer of nonwoven material asmentioned above. In such embodiments, the conductive ink forming therespective traces 136 a, 136 b and redundancy means 160, 160′, 190, 200,210, 220 is printed or otherwise deposited on the first layer of thebacksheet 34, 134. The present disclosure also contemplates embodimentsin which the incontinence detection pad 20 having redundancy means 160,160′, 190, 200, 210, 220 further includes fluid filter layer 28, 28 a,28 b, as the case may be, that is situated so as to inhibit a low volumeof fluid from being able to reach the first and second electrode traces136 a, 136 b beneath the absorbent core 26.

Referring now to FIG. 19, an alternative embodiment of an incontinencedetection pad 320 includes, from top to bottom, a topsheet 322 ofnonwoven material, a moisture absorbent core 326 beneath the topsheet,passive RFID tag 30 beneath the moisture absorbent core 326, an insertlayer 330 also beneath the moisture absorbent core 326 and havingelectrodes 336 a, 336 b printed thereon, a first layer 344 of abacksheet 334 beneath the insert layer 330, and a second layer 348 ofthe backsheet 334 beneath the first layer 344 of the backsheet 334. Insome embodiments, topsheet 322 is made of a fluid permeable material andfirst layer 344 of backsheet 334 is made of a fluid impermeablematerial. The adhesive used to couple topsheet 322, absorbent core 326,insert layer 330, and layers 344, 348 of backsheet 334 together is notshown in FIG. 19 but such adhesive is similar to that described above inconnection with the disclosed embodiments of incontinence detection pad20.

As shown in FIG. 19, absorbent core 326 and insert layer 330 are bothsituated between the topsheet 322 and the backsheet 334. Moreparticularly, insert layer 330 is situated between the backsheet 334 andthe absorbent core 326. The insert layer 330 includes a substrate 350and a conductive ink pattern that is provided on the substrate and thatis configured to form a first electrode trace 336 a and a secondelectrode trace 336 b. The passive RFID tag 30 is also provided on thesubstrate 350 and has electrical contacts that couple to the first andsecond electrode traces 336 a, 336 b.

There are a number of manufacturers that make absorbent pads forplacement beneath patients to absorb and retain incontinence to preventthe incontinence from leaking onto the beds of the patients. Suchabsorbent pads oftentimes include topsheet 322, absorbent core 326, anda multi-layer backsheet 334 like those depicted in FIG. 19. However,these manufacturers do not make absorbent pads that have any electricalcircuitry like that provided by electrode traces 336 a, 336 b andpassive RFID tag 30. By providing the electrode traces 336 a, 336 b andtag 30 on substrate 350 of insert layer 330, the insert layer 330 can beadded into existing absorbent pads during the manufacturing process toupgrade such pads into incontinence detection pads having circuitry todetect the incontinence and provide a wireless output signal indicativeof the detected incontinence.

Construction of the existing absorbent pads occurs at very high speedswith rolls of material being provided for each of the topsheet 322,absorbent core 326, and a multi-layer backsheet 334. These are unrolled,adhered together, and cut at a rate of up to 300 pads per minute in someembodiments. In order to maintain such high manufacturing speeds wheninsert layer 330 is added into the combination, the present disclosurecontemplates that the printing of traces 336 a, 336 b onto substrate 350and the attachment of tag 30 to substrate 350 occurs separately from themanufacturing process which unrolls, adheres, and cuts the topsheet 322,absorbent core 326, and a multi-layer backsheet 334. Thus, rolls ofinsert layers 330 are manufactured for subsequent use. In someembodiments, the rolls of insert layers 330 are then laminated torespective rolls of absorbent core material such that the insert layers330 and absorbent core 326 are supplied in the same roll of material.The roll of laminated insert layers 330 and absorbent cores 326 is thenused in the manufacturing process just like the rolls of absorbent corematerial that does not include any insert layers 330 laminated thereto.In order to contain or minimize cost, this disclosure contemplates thatsubstrate 350 of insert layer 330 comprises a relatively inexpensivematerial. For example, in some embodiments, the substrate 350 is made ofa paper or a cellulosic nonwoven material or tissue paper.

In an alternative embodiment, the substrate 350 of the insert layer 330comprises a standard sheet of paper (e.g., 8.5 inch by 11 inch sheet ofpaper or an A4 sheet of paper) and electrodes 336 a, 336 b are printedon the standard sheet of paper with RFID tag 30 also being attached tosheet of paper with its inputs coupled to electrodes 336 a, 336 b. Theinsert layer 330 formed by the sheets of paper with traces 336 a, 336 band tag 30 thereon are then assembled into a standard incontinence padduring manufacture to convert it to an incontinence detection pad withwireless communication capability.

As noted above, the backsheet 334 includes first and second layers 344,348. The first and second layers 344, 348 of the backsheet 334 arecoupled together with a hot melt adhesive in some embodiments.Alternatively or additionally, the backsheet 334 further include asecond layer 348 of polypropylene and, optionally, these first andsecond layers 344, 348 of the backsheet are coupled together with a hotmelt adhesive.

In some embodiments, the incontinence detection pad 320 further includea fluid filter layer which is substantially similar to those discussedabove in connection with FIGS. 1 and 2. It is contemplated that thefluid filter layer is situated between the absorbent core 326 and theinsert layer 330. The fluid filter layer of pad 320 is configured toinhibit a low volume of fluid from being able to reach the first andsecond electrode traces 336 a, 336 b on the substrate 350 of the insertlayer 330. After fluid of a sufficient volume greater than the lowvolume has passed through the topsheet 322, the absorbent core 326, andthe fluid filter layer (e.g., layer 28, 28 a, 28 b, as the case may be),an electrical pathway is formed between the first and second electrodetraces 336 a, 336 b by the fluid which enables the passive RFID tag 30to emit a signal, in response to the passive RFID tag 30 being excitedby external energy, that indicates an incontinence event may haveoccurred.

Optionally, the fluid filter layer of incontinence detection pad 320 ismade from any of the materials mentioned above in connection with fluidfilter layers 28, 28 a, 28 b, including being made from a hydrophobicpolymeric nonwoven material or a hydrophilic material. For example, sucha hydrophobic polymeric nonwoven material may comprise one or more ofthe following: a spunbond material, a spunlace material, a meltblownmaterial, or a meltspun material. If desired, the hydrophobic polymericnonwoven material may include a polypropylene or polyethylene materialhaving a pore size and basis weight that may be configured to preventthe low volume of fluid from penetrating therethrough due to surfacetension of the fluid. In some embodiments of the incontinence detectionpad 320, the electrode traces 336 a, 336 b include redundancy means 160,160′, 190, 200, 210, 220 as described above.

In still another variant embodiment, substrate 350 of the insert layer330 comprises a liquid filter layer, similar to layer 28 describedabove, and electrodes 336 a, 336 b are printed on the liquid filterlayer with RFID tag 30 also being attached to liquid filter layer withits inputs coupled to electrodes 336 a, 336 b. Sheets of low densitypolyethylene (LDPE), high density polyethylene (HDPE), polyethyleneterephthalate (PET), or polypropylene are examples of suitable materialwhich may serve the dual purpose as liquid filter layers and substrates350 of insert layers 330. In such embodiments, it is contemplated thatthe dual purpose liquid filter layer/substrates 350 are inserted intostandard incontinence pads upside down, or in other words with theelectrode traces 336 a, 336 b and tag 30 on the bottom surface of thesubstrate 350, assuming the backsheet 334 is below the substrate 350 andthe topsheet 322 is above the substrate 350 as shown in FIG. 19, forexample. In such embodiments, fluid volumes above the low volume offluid that is blocked by the liquid filter layer, will eventually leechor absorb through the liquid filter layer/substrate 350 and bridge theelectrodes 336 a, 336 b to form a closed circuit configurationindicating that the pad 320 is wet.

Adaptive Power Control

Use of RFID tags for incontinence detection has proven to be anythingbut straightforward. There are many nuances to interacting with the RFIDtag, given the wide dynamic range of signals that the tag is likely toexperience being firmly in the nearfield radiation zone of the antenna,being from 0 to at most ½ λ from the antenna. Receive signal strength atthe tag can vary from an essentially unattenuated, +37 dBm signal, downto the edge of the detection (−18 dBm for the embodiments contemplatedherein and in International Publication No. WO 2017/087452 A1 and U.S.application Ser. No. 15/596,036 which are already incorporated herein byreference, collectively “the incontinence detection systems”) and below.Excessive transmit power has been shown to cause spurious false wetindications in the RFID tag, causing convoluted detection algorithms tobe implemented in order to attempt to weed out successive strings of wetindications that may or may not be valid.

There are several indications available to the system that the inlay haseither ample signal or more than ample signal required to perform itsfunction. These may be exploited to control the output RF power in amore logical fashion than just transmitting +32 dBm into the +5 dBm gainantenna just because that is what is required in certain patient/padconfigurations to allow the required pad read reliability to be realizedacross the entire defined read range for all patient body mass indexes(BMI's) in the range for which known non-bariatric beds are typicallyrated.

There are a number of indicators that the system either has ample signalor too much signal for the current patient/pad configuration (e.g., howthe patient is placed on the pad and where the pad is on the definedread grid). Firstly, there is an indication in the status read back fromthe RFID tag that shows when an external power flag is set. The RFIDchip of the RFID tags contemplated for use in the incontinence detectionapplication is passively powered (parasitically from the EM field aroundthe transmit antenna) and if a tamper input of the RFID chip shows thatthe chip thinks it is being externally powered, then there is clearlytoo much signal present and the power transmitted to the RFID tag can bereduced.

Another indicator that there is ample or too much signal is the numberof transmit/receive (TX/RX) antenna combinations from which the RFID tagmay be read. In some of the contemplated incontinence detection systems,there are a total of 12 combinations of one transmit antenna and threereceive antennas (a total of 4 antennas, any one of which may be used aseither a TX or a RX antenna). If a significant number of thecombinations yield good reads, the system may be on the edge of havingtoo much power available in some of the combinations.

Hardware of a reader that controls the transmissions from the designatedTX antenna and that reads data received by one or more of the RXantennae has a feature which allows a receive signal level (RSL) figureof merit (FoM) to be read from a receiver of the hardware. In the past,this signal has been shown to be noisy and unreliable, but if applied toeach TX/RX combination individually (i.e. a total of 12 FoM for receivequality) and sufficient averaging applied, a reliable indicator may beconstructed which shows how well an RFID tag is receiving based on thestrength of its transmit signal. This can be used as a clue as to howthe channel is behaving on a TX/RX combination basis. At this point, apower control algorithm can be implemented on either a global level(one-size fits all transmit power, with the strongest combinationssetting the power level) or on an individual TX/RX pair basis.

Because the incontinence detection systems exhibit good short termstability in terms of the RFID tag signal levels, both receive andtransmit (there is no Rayleigh fading or time varying channel effectssuch as are seen in a mobile telephone environment), the signals exhibitcyclostationarity. There are nulls in the receive signal for differentlocations on the defined detection grid superimposed on the bed surface,but again they are cyclostationary and vary slowly with time, allowingfor a small signal linearization approximation to be used. This shouldallow for a dynamic control of the output power to accommodate a widerange of path losses such as have been seen and documented in thedevelopment of the incontinence detection systems.

The transmit chain of the incontinence detection systems can output from+20 dBm to +33 dBm (e.g., more than a 10 dB range) under softwarecontrol without any hardware modifications at all. Changes inpad/patient configuration can easily be accounted for when the receiveFoM's deteriorate at the receiver, allowing for the output power to bechanged to bring the system into the optimal configuration for reading atag in a given location, which counter-intuitively, is not necessarilythe configuration where the maximum number of reads of an RFID taglocated in a given place with a given patient configuration. Two RFIDtag parameters are simultaneously being balanced against each other,e.g. P(successful valid read) and P(RF power induced false wet). Bothare controlled and influenced by the transmit output power. Using aTX/RX pair computed signal to noise ratio (SNR) RSL FoM to guide TXpower can result in the optimal P(successful valid read) whileminimizing P(false wet indication).

The output power to the transmit antenna is adjusted via software from aRFID reader chip, the AS3993/ST25RU2993 reader chip in some embodiments,of a power controller. In such embodiments, there is a register thatprovides 19 dB range from 0 dBm out to −19 dBm out by varying the RFoutput level from the reader chip. This signal is then amplified by adriver and final amplifier of the power controller. See FIGS. 29A-29Cand the related discussion, particularly FIG. 29C, of InternationalPublication No. WO 2017/087452 A1 which is already incorporated hereinby reference. The 19 dB of dynamic range on the output is not actuallyobtained because the final RF amplifier is very heavy in gaincompression (at least about 6 dB to about 9 dB). By adjusting anattenuator network on an output of the driver amplifier, a range ofabout 13 dB on the power output, roughly from about +18 dBm to about +31dBm or so is achievable.

Referring now to FIG. 20 for purposes of further illustrating theconcepts of the above discussion regarding Adaptive Power Controlcontemplated herein, a bed 400 includes a bed frame 402 and a mattress404 supported on bed frame 402. Incontinence detection pad 20 issituated between mattress 404 and a patient and is operable to detectincontinence from the patient. Incontinence detection pad 20 isillustrated generically in FIG. 20 but any of the incontinence detectionpads 20, 320 contemplated herein, as well as any of the incontinencedetection pads contemplated in International Publication No. WO2017/087452 A1 which is already incorporated herein by reference mayjust as well be used. A reader 406 is coupled to bed frame 404. Aplurality of antennae 408 a, 408 b, 408 c, 408 d, 408 n is also coupledto bed frame 402, such as being coupled to one or more sections of anarticulated mattress-support deck (not shown) of bed frame 402.

Each antennae 408 a, 408 b, 408 c, 408 d, 408 n is electrically coupledto a switch matrix 410 of reader 406. Switch matrix 410 is operable todetermine which antenna 408 a, 408 b, 408 c, 408 d, 408 n is thedesignated transmit antenna and which of antennae 408 a, 408 b, 408 c,408 d, 408 n are the receive antennae. In the illustrative example ofFIG. 20, antenna 408 a is designated as the transmit antennae and theremaining antennae 408 b, 408 c, 408 d, 408 n are the receive antennae.Reader 406 applies power to transmit antenna 408 a which produces anelectromagnetic field to power the passive RFID tag 30 of pad 20 andantennae 408 b, 408 c, 408 d, 408 n are activated one at a time byswitch matrix 410 resulting in a receiver 412 of reader 406 beingoperated to “listen” for a backscattered signal emitted from tag 30 andreceived by the activated receive antenna 408 b, 408 c, 408 d, 408 n.

Reader 406 includes an analyzer 414 that is electrically coupled toreceiver 412. Analyzer 414 is operable to analyze the backscatteredsignal, if any, received by receiver 412 from the activated receiveantenna 408 b, 408 c, 408 d, 408 n. Thus, analyzer 414 determines theTX/RX SNR and the RSL FoM and also performs the averaging of thereceived backscattered signals. In some embodiments, analyzer 414determines if the backscattered data indicates that a power flag hasbeen set by the RFID tag 30. Based on the analysis of the signals fromthe various TX/RX pairs of antennae 408 a, 408 b, 408 c, 408 d, 408 n, apower controller 416 of reader is operated to adjust the power levelthat is applied to the designated transmit antenna 408 a, 408 b, 408 c,408 d, 408 n. As noted above, the goal is to reduce the transmit powerlevel so as to reduce the number of false wet positives that are inducedin RFID tag 30 by the electromagnetic field generated by the transmitantenna 408 a, 408 b, 408 c, 408 d, 408 n.

Reader 406 is coupled to bed circuitry 418 of bed 400. Thus, if thebackscattered signal from RFID tag 30 includes data indicating thatincontinence detection pad 20 is wet, reader 406 operates to notify bedcircuitry 418 of the wet condition of pad 20 and, in turn, bed circuitryactivates an on bed alert 420. Alert 420 includes, for example, anaudible alert, a textual or graphical message shown on a display screenof bed 400, or an on bed alert light being illuminating in a particularmanner (e.g., causing the alert light to illuminate a yellow or ambercolor). In some embodiments, bed circuitry 418 sends a message to aremote alert 424, such as via a network 422 of a healthcare facility.Remote alert 424 includes, for example, a remote computer, such as amaster nurse station computer, which displays a textual or graphicalmessage on a display indicating that the pad 20 is wet, a caregiversmobile device which displays a textual or graphical message indicatingthat the pad 20 is wet, or an indicator light (aka dome light) of anurse call system that is located in a hallway adjacent the patient'sroom being illuminated in a particular manner.

So, based on the forgoing, the present disclosure contemplates a methodof controlling an incontinence detection system. The method includesestablishing a first antenna 408 a, 408 b, 408 c, 408 d, 408 n of aplurality of antennae 408 a, 408 b, 408 c, 408 d, 408 n as a transmitantenna that is used to wirelessly energize a passive RFID tag 30 of anincontinence detection pad 20 at a first power level. The plurality ofantennae 408 a, 408 b, 408 c, 408 d, 408 n includes N spaced apartantennae, with N being an integer equal to or greater than three. Themethod further includes establishing each of the plurality of antennae408 a, 408 b, 408 c, 408 d, 408 n, except for the first antenna, asreceive antennae that each listen for backscattered data emitted fromthe passive RFID tag 30. The method further includes reducing the firstpower level to a second power level if the receive antennae that areable to read the backscattered data exceeds a predetermined number ofreceive antennae and the predetermined number being less than N−1.

In some embodiments, the method further includes analyzing signal tonoise ratio between the transmit antenna and each of the receive antennabefore reducing the first power level to the second power level.Alternatively or additionally, the method further includes analyzing areceive signal level (RSL) figure of merit (FoM) of the backscattereddata before reducing the first power level to the second power level.Optionally, the RSL FoM of multiple emissions of backscattered data isaveraged before reducing the first power level to the second powerlevel. Further alternatively or additionally, the method furtherincludes determining that an external power flag is set in thebackscattered data before reducing the first power level to the secondpower level.

In some embodiments, the predetermined number of receive antennaeincludes two receive antennae. That is, the power level is reduced untilonly two receive antennae are able to receive the backscattered signalfrom tag 30. Alternatively, the predetermined number of receive antennaeincludes one receive antenna. That is, the power level is reduced untilonly one receive antenna is able to receive the backscattered signalfrom tag 30. In some embodiments, the first power level and the secondpower level lie within a range of about +20 decibel milliWatt (dBm) toabout +33 dBm.

In some embodiments, the method further includes cycling through theplurality of antennae as being established as the transmit antenna witheach of the remaining antennae of the plurality of antennae beingestablished as the receive antenna for a period of time. Optionally, theplurality of antennae are coupled to a bistatic radio frequency (RF)switch matrix which is operable to establish which antenna of theplurality of antennae is the transmit antenna and to establish whichantenna of the plurality of antennae is the receive antenna. See FIG. 8and the related discussion in U.S. application Ser. No. 15/596,036 whichis already incorporated herein by reference. In some embodiments, themethod further includes operating the bistatic RF switch matrix to causethe transmit antenna to transmit using a frequency hopping scheme. Thefrequency hopping scheme may use 50 distinct frequencies, for example,with each frequency being used only once in a pseudo-random order beforeany of the 50 frequencies are repeated. In some embodiments, the 50frequencies lie within a range between about 902 MegaHertz (MHz) andabout 928 MHz.

Referring now to FIG. 21, an absorbent article 500 includes a substrate502, a first electrode 504 on the substrate 502, a second electrode 506on the substrate 502 and circuitry 508 coupled to the electrodes 504,506. The second electrode 506 is spaced from the first electrode 504.Circuitry 508 is operable to monitor whether a biofluid is present onthe substrate in a sufficient volume (e.g., greater than a low volume asdiscussed above) by determining whether the first and second electrodes504, 506 are in an open circuit configuration or a closed circuitconfiguration. The open circuit configuration is indicative of anabsence of biofluid and the closed circuit configuration is indicativeof a presence of biofluid. The absorbent article 500 further includes aplurality of high wick bridges 510 that interconnect the first andsecond electrodes 504, 506.

In the illustrative embodiment, the first electrode 504 include a pairof generally straight segment 504 a interconnected by a generallysemi-circular segment 504 b. The second electrode 506 includes agenerally straight segment 506 a that is substantially parallel with,and located between, straight segments 504 a. Each of the high wickbridges include a generally straight main segment 512 and a series ofhash segments 514. In some embodiments, the main segment 512 of at leastsome of the high wick bridges 510 are substantially perpendicular to thefirst and second segments 504 a, 506 a of the respective electrodes 504,506. In this regard about 80 degrees to about 110 degrees is consideredto be substantially perpendicular according to the present disclosure.

In the illustrative embodiment, each has segment 514 of the series ofhash segments 514 is substantially perpendicular with the associatedmain segment 512. The main segment 512 bisects each of the hash segments514 in the illustrative example, but this need not be the case.Furthermore, the hash segments 514 are each of substantially equivalentlengths in the illustrative example, but this also does not need to bethe case. Each of the high wick bridges 510 has four hash segments 514associated with each main segment 512 but the present disclosurecontemplates that more or less hash segments 514 than four, including nohash segments 514 at all, may be associated with the respective mainsegments 512. Different main segments 512 may have a different number ofhash segments 514 associated therewith, if desired.

In some embodiments in including the illustrative embodiment, theabsorbent article 500 further includes a hydrophobic material situatedwithin each of a plurality of zones 516. Zones 516 are bounded generallyby respective portions of the first and second electrodes 504, 506 andby respective pairs of adjacent high wick bridges 510. The hydrophobicmaterial may comprise a hydrophobic coating or hydrophobic material ofany of the types discussed hereinabove, for example. As shown in FIG.21, the hydrophobic material in at least some of the zones 516 isquadrilateral in shape. Ends of the hash segments 514 each terminate ata respective boundary of a corresponding zone 516 in the illustrativeembodiment. In other embodiments, the ends of hash segments 514 arespaced from, but are in close proximity to, a respective boundary of thehydrophobic material in each zone 516. It should be appreciated that thecircuitry 508 may include a radio frequency identification (RFID) tagsuch as any of the passive RFID tags discussed hereinabove. Optionally,circuitry 508 may comprise an active RFID tag that is powered with abattery or other power source.

Liquid, such as urinary incontinence, runs off of the hydrophobicmaterial of each of zones 516 and is collected by the hash segments 514of the respective high wick bridges 510 situated between zones 516. Hashsegments 514 direct the moisture or wetness to the respective mainsegment 512 of the corresponding high wick bridges 510. After an mainsegment 512 is wetted from one end to the other, a closed circuitconfiguration is established between electrodes 504, 506 and circuitry508 provides a signal indicating that pad 500 is wet, either viabackscattered data in response to being irradiated with energy in thecase of a passive RFID tag, or via an active transmission in the case ofan active RFID tag.

By providing pad 500 with high wick bridges 510 between electrodes 504,506 and with hydrophobic zones 516, the sensitivity of pad 500 isincreased as compared to a similarly constructed pad without bridges 510or zones 516. That is, a smaller volume of fluid will result in a closedcircuit configuration being created between electrodes 504, 506.Furthermore, by configuring bridges 510 and/or zones appropriately, thefluid deposited on the pad 500 can be directed away from the regions ofthe pad 500 over which a patient is expected to be. Thus, skin breakdowndue to moisture is alleviated or reduced in such embodiments. Once themoisture is directed way from the patient by the high wick bridges 510and hydrophobic zones 516, the moisture is able to evaporate from thepad 500 more easily.

Embodiments of pad 500 having high wick bridges 510 but withouthydrophobic zones 516 are contemplated by this disclosure as areembodiment having spaced apart hydrophobic zone 516 but without highwick bridges 510. It should be appreciated that pad 500 includes one ormore of the various other layers of material discussed above. Forexample, substrate 502 of pad 500 comprises the backsheet (e.g., doublelayer of material as discussed above) in some embodiments and anabsorbent core and a top sheet is also provided in the pad along withthe various adhesive material to couple these layers together. A fluidfilter layer of any of the types discussed above also may be included inpad 500 although, the purpose of the filter layer to prevent low volumesof fluid from creating false positive readings is at odds with thepurpose of the high wick bridges 510 and hydrophobic zones 516 toincrease the sensitivity of pad 500 to output “wet” readings at lowervolumes of fluid. In any event, there may be situations in which adesigner may wish to have a higher moisture detection sensitivity in oneor more regions of pad 500, in which case bridges 510 and/or zones 516are provided in such region(s), and to have a lower moisture detectionsensitivity in other regions of the pad 500, in which case a fluidfilter layer is provided in such other region(s).

Referring now to FIG. 22, an absorbent article 520 includes a substrate522, a first series 524 of spaced apart hydrophilic fluid guide paths526 located on a right side of the substrate 522, and a second series528 of spaced apart hydrophilic fluid guide paths 530 located on a leftside of the substrate 522. The first and second hydrophilic guide paths526, 530 of the respective first series 524 and second series 528 aremirror images of each other in the illustrative example. Inner ends ofeach guide path 526 are spaced apart from a corresponding end of acompanion guide path 530. The hydrophilic fluid guide paths 526, 530 areeach configured to direct moisture away from a patient situated atop acentral region of the substrate 522 as indicated by the patientfootprint 532 (in dotted).

Each fluid guide path 526, 530 of the respective first and second series524, 528 of fluid guide paths 526, 530 extend from the central region ofthe substrate 522 beyond the footprint 532 of the patient's body to arespective side region of the substrate beyond the footprint 532 of thepatient's body. Thus, for discussion purposes, portions of pad 520inside footprint 532 are considered to be in the central region of pad520 or substrate 522, and portions of pad 520 outside of footprint 532are considered to be the side regions of pad 520 or substrate 522.

Evaporation of moisture in the side regions of pad 520 on opposite sidesof the footprint 532 produce a moisture gradient within the hydrophilicfluid guide paths 526, 530 so that moisture within the footprint 532moves outwardly to the side regions away from the patient. Furthermore,pressure produced on the fluid guide paths 526, 530 by the patient inthe central region results in moisture moving outwardly to the sideregions away from the patient. In the illustrative example, thesubstrate 522 is generally rectangular in shape and each fluid guidepath 526, 530 of the first and second series 524, 528 of guide paths526, 530 is oriented generally along a long dimension of the substrate.With regard to the high wick bridges 510 and hydrophilic fluid guidepaths discussed above, examples of suitable hydrophilic materials havinghigh wick rates include the following materials: polypropylene, MerylSkinlife®, SORBTEK™, and Poro-Tex expanded PTFE (ePTFE).

In some uses, pad 520 is placed upon a mattress having a microclimatemanagement (MCM) layer at the top of the mattress. Air is blown throughthe MCM layer to wick moisture away from the patient above the MCM layerthereby to keep the interface between the patient and the mattressrelatively dry. The air moving through the MCM layer will tend to dryout the side regions of pad 520 more so than the central region of pad520 beneath the patient. As the side regions dry due to the air movingin the MCM layer, a moisture gradient is created so that moisture morereadily moves from the central region of pad 520 to the side regions.This same phenomenon occurs due to exposure of the side regions of pad520 to ambient air without the use of an MCM layer, but having an MCMlayer with actively moved air enhances the evaporation rate at the sideregions of pad 520.

In a variant embodiment, a hydrophobic material (e.g., layer or coating)is provided in the central region of pad 520 so that incontinence orother biofluid is spread away from the central region due to pressure bythe weight of the patient in the central region. The hydrophobicmaterial has side boundaries that terminate at or near the side regionsof pad 520, such as in the vicinity of the dotted lines of footprint 532so that an absorbent material, such as the illustrative fluid guidepaths 526, 530, collect the moisture as it moves outwardly to the sideregions from beneath the patient. Humidity adjacent the patient's isreduced in each of the embodiments just described in connection withFIG. 22. Thus, skin damage is reduced because the patient's exposure tourine and other biofluids is reduced.

As noted above in connection with FIG. 9B, backsheet 134 includesbreathable low density polyethylene (LDPE) film 144 which serves as anupper layer of the backsheet 134 and a layer of polypropylene (PP)spunbond nonwoven material 148 which serves as a lower layer of thebacksheet 134 when the associated incontinence detection pad is in usebeneath a patient with the backsheet 134 at the bottom of theincontinence detection pad. In a similar manner, backsheet 334 of FIG.19 includes upper layer 344 and lower layer 348. Backsheet 46 ofincontinence detection pad 20 of FIGS. 1-3 is similarly constructed witha two-layer backsheet in some embodiments. The discussion below willrefer to film 144 and nonwoven material 148 but the discussion isequally applicable to layers 344, 348 and to two-layer embodiments ofpad 20 constructed with these same or substantially similar materials.

While LDPE film 144 is fluid impermeable, it is a breathable film whichhas moisture vapor permeability. Thus, film 144 is a microporous(breathable) polyethylene film. Of course, the PP spunbond nonwovenmaterial 148 of backsheet is very porous to both air and liquid. Themicroporous nature of film 144 renders it porous to air and moisturevapor due to microfractures introduced by using a calcium carbonatefiller. Although film 144 is not porous to water (e.g., film 144 isimpermeable to liquid), it is so thin, on the order of about 0.001inches in illustrative embodiments, that it has been found that theconductive ink of electrode traces 36 a, 36 b, 136 a, 136 b, 336 a, 336b, as the case may be, sometimes seeps into the microfractures and/orwater vapor accumulates beneath the associated incontinence detectionpad to such an extent that electrodes 36 a, 36 b, 136 a, 136 b, 336 a,336 b become electrically connected in a closed circuit arrangement fromunderneath the pad. This results in a false positive incontinencedetection alarm being generated.

Also, when a soiled incontinence detection pad is removed from beneath apatient, caregivers typically clean the patient with wet sponges and/ortowels which may get the underlying bedsheets wet and, in someinstances, caregivers may change the bed sheets and wipe down an uppersurface of the mattress ticking (e.g., the outer surface of themattress). In either case, there is sometimes enough fluid or moisturefrom the sponges or towels, or left on the upper surface of the mattressticking from the cleaning process, that the bed sheets becomesufficiently damp or moist that the moisture is able to seep through thenonwoven material 148 and into the microfractures of the film 144,thereby resulting in electrodes 36 a, 36 b, 136 a, 136 b, 336 a, 336 bbecoming electrically connected in a closed circuit arrangement fromunderneath the pad. This is another way in which false positiveincontinence detection alarms may be being generated.

To alleviate the false alarming problem described in the preceding twoparagraphs, the present disclosure contemplates that an alternativeembodiment incontinence detection pad 620 has an additional liquid orfluid filter layer 28′ or 28″ or 28′″ located underneath the electrodetraces 36 a, 36 b as shown in FIG. 23. In one version of pad 620, liquidfilter layer 28′ includes liquid filter layer portions 28 a′, 28 b′located directly beneath electrode traces 36 a, 36 b and above film 144of the associated backsheet 134. Portions 28 a′, 28 b′ have the samegeometry as respective electrode traces 36 a, 36 b, but are wider (e.g.,about 3 mm to about 25 mm) than the width of electrode traces 36 a, 36 b(e.g., about 1 mm to about 3 mm). In fact, the geometry of portions 28a′, 28 b′ beneath electrodes 36 a, 36 b is substantially the same as thegeometry of portions 28 a, 28 b of the liquid filter layer above theelectrodes 36 a, 36 b in the illustrative example, but this need not bethe case in other embodiments.

In some embodiments, electrodes 36 a, 36 b are printed onto portions 28a′, 28 b′, respectively, either before or after portions 28 a′, 28 b′are applied to film 144. In other embodiments, electrodes 36 a, 36 b areprinted on a bottom surface (as oriented in FIG. 23) of portions 28 a,28 b of the overlying fluid filter layer. During manufacture, the bottomsurface of portions 28 a, 28 b may be facing upwardly during the processof printing electrodes 36 a, 36 b thereon. In a further variant, theelectrodes 36 a, 36 b are printed on a substrate 350 of an insert layer330, as described above in connection with FIG. 19, and the insert layer330 with electrodes 36 a, 36 b (and RFID tag 30) is situated beneathfluid filter layer portions 28 a, 28 b and above fluid filter layerportions 28 a′, 28 b′.

In another version of pad 620, a liquid filter layer 28″ includes liquidfilter layer portions 28 a″, 28 b″ located beneath film 144 and abovenonwoven material 148 of backsheet 134. Portions 28 a″, 28 b″ arealigned with electrodes 36 a, 36 b, respectively, and have the samebasic geometry as electrodes 36 a, 36 b, but like layer 28′, are wider(e.g., about 3 mm to about 25 mm) than the width of electrodes 36 a, 36b (e.g., about 1 mm to about 3 mm). In yet another version of pad 620, aliquid filter layer 28′″ includes liquid filter layer portions 28 a′″,28 b′″ located beneath nonwoven material 148 of backsheet 134. Portions28 a′″, 28 b′″ are aligned with electrodes 36 a, 36 b, respectively, andhave the same basic geometry as electrodes 36 a, 36 b, but like layers28′ and 28″, are wider (e.g., about 3 mm to about 25 mm) than the widthof electrodes 36 a, 36 b (e.g., about 1 mm to about 3 mm). Thus, in someembodiments, the layers 28′, 28″, 28′″ depicted in FIG. 23 are mutuallyexclusive in that only one of layers 28′, 28″, 28′″ is present in anygiven version of pad 620. In other embodiments, any two of layers 28′,28″, 28′″ are present in further versions of pad 620. If desired, allthree of layers 28′, 28″, 28′″ are present in still a further variant ofpad 620.

As shown in FIG. 23, in addition to electrodes 36 a, 36 b, backsheet134, and one or more of fluid filter layers 28′, 28″, 28″, pad 620 alsoincludes topsheet 22, layer 24 of slot coated adhesive beneath thetopsheet 22, moisture absorbent core 26 beneath the layer 24 ofadhesive, the upper fluid filter layer having portions 28 a, 28 bbeneath the absorbent core 26, passive radio frequency identification(RFID) tag 30, and perimeter adhesive layer 32. The discussion aboveregarding elements 22, 24, 26, 28 a, 28 b, 30, 32, 36 a, 36 b, 134, 144,148 in connection with various incontinence detection pad embodiments isequally applicable to incontinence detection pad 620 for these variouscomponents. Furthermore, the discussion above regarding the features ofthe filter layer 28 a, 28 b, including the materials from which filterlayer 28 a, 28 b may be made, is equally applicable to filter layers28′, 28″, 28″ and their respective portions 28 a′, 28 b′, 28 a″, 28 b″,28 a″, 28 b′″.

Optionally, in some embodiments of pad 620, filter layers 28′, 28″, 28′,as the case may be, and their respective portions 28 a′, 28 b′, 28 a″,28 b″, 28 a″, 28 b′″ are made of a material that is both fluidimpermeable and moisture vapor impermeable. Vinyl material is an exampleof such material. It is also within the scope of the present disclosurethat film 144 and/or nonwoven material 148 is made of a material that isless moisture vapor permeable, including making either or both of layers144, 148 of backsheet 134 from a fluid impermeable and moisture vaporimpermeable material such as vinyl material. However, it is preferablefor patient comfort to have a breathable backsheet 134 if possible. Evenin embodiments using fluid/moisture vapor impermeable filter layers 28′,28″, 28″ having respective portions 28 a′, 28 b′, 28 a″, 28 b″, 28 a″,28 b″, the majority of the surface area of backsheet 134 is stillmoisture vapor permeable or breathable.

Referring now to FIG. 24, instead of having layers 28′, 28″, 28′ withportions 28 a′, 28 b′, 28 a″, 28 b″, 28 a″, 28 b″ that generally matchthe geometry of electrodes 36 a, 36 b, the present disclosurecontemplates several versions of an incontinence detection pad 720 thathave one or more rectangular fluid filter layers 28 c′, 28 c″, 28 c′″.In a first version of pad 720, fluid filter layer 28 c′ is locateddirectly beneath electrode traces 36 a, 36 b and above film 144 of theassociated backsheet 134. In some embodiments, electrodes 36 a, 36 b areprinted onto layer 28 c′, either before or after layer 28 c′ is appliedto film 144. In other embodiments, electrodes 36 a, 36 b are printed ona bottom surface (as oriented in FIG. 24) of portions 28 a, 28 b offluid filter layer 28. During manufacture, the bottom surface ofportions 28 a, 28 b may be facing upwardly during the process ofprinting electrodes 36 a, 36 b thereon as noted above. In a furthervariant, the electrodes 36 a, 36 b are printed on a substrate 350 of aninsert layer 330, as described above in connection with FIG. 19, and theinsert layer 330 with electrodes 36 a, 36 b (and RFID tag 30) issituated beneath fluid filter layer portions 28 a, 28 b and above fluidfilter layer portions 28 c′.

In another version of pad 720, a liquid filter layer 28 c″ is locatedbeneath film 144 and above nonwoven material 148 of backsheet 134. Inyet another version of pad 720, a liquid filter layer 28 c′″ is locatedbeneath nonwoven material 148 of backsheet 134. Thus, in someembodiments, the layers 28 c′, 28 c″, 28 c′″ depicted in FIG. 24 aremutually exclusive in that only one of layers 28 c′, 28 c″, 28 c′″ ispresent in any given version of pad 720. In other embodiments, any twoof layers 28 c′, 28 c″, 28 c′″ are present in further versions of pad720. If desired, all three of layers 28 c′, 28 c″, 28 c′″ are present instill a further variant of pad 620. Fluid filter layers 28 c′, 28 c″, 28c″ shown in FIG. 24 have outer peripheries that are coextensive with theouter peripheries of layers 144, 148 of backsheet 134 and/or with theouter periphery of topsheet 22. In other embodiments, fluid filterlayers 28 c′, 28 c″, 28 c′″ have outer peripheries that are coextensivewith absorbent core 26.

In still further versions of pad 720, fluid filter layer 28 a, 28 b isomitted and a fluid filter layer 28 (shown in phantom in FIG. 24) havinga rectangular shape is used instead. This fluid filter layer 28 may beused in any of the embodiments of pad 720 described herein in lieu offluid filter layer 28 a, 28 b. Thus, pads 720 having upper fluid filterlayer 28 in combination with any one or more of lower fluid filterlayers 28 c′, 28 c″, 28 c′″ are contemplated by this disclosure. Thediscussion above of fluid filter layer 28 of FIG. 1 in connection withincontinence detection pad 20 is equally applicable to the fluid filterlayer 28 when used in any of the contemplated embodiments of pad 720.

As shown in FIG. 24, in addition to electrodes 36 a, 36, backsheet 134,and one or more of fluid filter layers 28 c′, 28 c″, 28 c′″, pad 670also includes topsheet 22, layer 24 of slot coated adhesive beneath thetopsheet 22, moisture absorbent core 26 beneath the layer 24 ofadhesive, fluid filter layer 28 (in phantom) or fluid filter layer 28 a,28 b beneath the absorbent core 26, passive radio frequencyidentification (RFID) tag 30, and perimeter adhesive layer 32. Thediscussion above regarding elements 22, 24, 26, 28, 28 a, 28 b, 30, 32,36 a, 36 b, 134, 144, 148 in connection with various incontinencedetection pad embodiments is equally applicable to incontinencedetection pad 720. Furthermore, the discussion above regarding thefeatures of filter layer 28 and filter layer 28 a, 28 b, including thematerials from which filter layer 28 and filter layer 28 a, 28 b may bemade, is equally applicable to filter layers 28 c′, 28 c″, 28 c′″.

Optionally, in some embodiments of pad 720, filter layers 28 c′, 28 c″,28 c″, as the case may be, are made of a material that is both fluidimpermeable and moisture vapor impermeable. As noted above, vinylmaterial is an example of such material. It is also within the scope ofthe present disclosure that film 144 and/or nonwoven material 148 of pad720 is made of a material that is less moisture vapor permeable,including making either or both of layers 144, 148 of backsheet 134 froma fluid impermeable and moisture vapor impermeable material such asvinyl material.

Referring now to FIG. 25, an alternative embodiment backsheet 134′ isshown having a different geometry or pattern of first and secondelectrode traces 136 a″, 136 b″ as compared to the electrode traces 36a, 36 b of the backsheet 34 shown in FIGS. 1-3 and as compared to theelectrode traces 136 a, 136 b of the backsheet 134 shown in FIG. 9A. Oneof the differences is that traces 136 a″, 136 b″ each include a quarterof a circle trace portion 138′ having a radius of about 121.5 mm in theillustrative example. Trace portions 138′ are located at diagonallyopposite corner regions of backsheet 134′. Trace 136 b″ also includes ahook portion 140′ at a terminal end thereof. Segments of electrodetraces 136 a″, 136 b″ other than portions 138′, 140′ are generallystraight, although, electrode trace 136 a″ has an inclined segment 135leading to redundancy means 160′″ of trace 136 a″ and electrode trace136 b″ has an inclined segment 137 spaced above redundancy means 160′″in FIG. 25, with segment 135 being longer that segment 137. Otheraspects of the patterns of traces 136 a″, 136 b″ on backsheet 134′ canbe readily gleaned from a visual inspection of FIG. 25. Backsheet 134′also has registration marks 141 a′, 141 b′ that are used during themanufacture of the incontinence detection pad in which backsheet 134′ isincluded.

Still referring to FIG. 25, an overall length 905 of backsheet 134′, andtherefore the overall length of the associated incontinence detectionpad, is about 900 mm and an overall width 907 of backsheet 134′, andtherefore the overall width of the associated incontinence detectionpad, is about 750 mm in the illustrative embodiment. Absorbent core 26is generally centered on backsheet 134′ has as a length of about 790 mmand a width of about 660 mm (see the dotted line rectangle in FIG. 9Awhich represents the footprint of absorbent core 26). Furthermore, angle902′ is about 45 degrees in the illustrative embodiment.

Additional dimensions of illustrative backsheet 134′ include thefollowing: dimension 904′ is about 697.0 mm, dimension 906′ is about525.0 mm, dimension 908′ is about 163.5 mm, dimension 910′ is about 88.5mm, dimension 912′ is about 182.0 mm, dimension 913′ between a segmentof electrode 136 b″ and a sacrificial trace portion 136 c′ is about 60.5mm, dimension 914′ is about 197.0 mm, dimension 918′ is about 182.0 mm,dimension 920′ is about 150.0 mm, dimension 920″ is about 165 mm, anddimension 922′ is about 88.5 mm. It should be appreciated that there isa tolerance range associated with each of the given dimensions. Suchtolerance ranges include ranges as high as about +/−4.0 mm and as low asabout +/−0.1 mm for the various dimensions and there is also a tolerancerange of about +/−0.5 degrees for angle 902′.

The dimensions given for the illustrative example of FIG. 25 areprovided for purposes of comparison such as, for example, dimension 914′is about 8.2% larger than dimension 912′ or dimension 918′. Also,dimension 914 is more than twice that of dimension 910′ or dimension922′. Many other similar comparisons can be made based on each of thegiven dimensions associated with pad 134′ such that each possiblecomparison is contemplated herein. In the illustrative example,dimension 904′ is generally centered along the overall length 905 ofbacksheet 134′.

Referring now to FIG. 26, a portion of a film layer 950 is showncarrying six RFID tag circuits 952 which, in turn, include RFIDelectrical inlays 58′ that are substantially the same as inlays 58 shownin FIGS. 5A and 5B, for example. The RFID tag circuits 952 also includethe respective RFID integrate circuit (IC) chips that are coupled toeach of inlays 58′ but that are too small to be discernible in FIG. 26.In some embodiments, inlays 58′ of FIG. 26 include gaps that are bridgedby resistors 76 according to, for example, any one or more of thevariants shown in FIGS. 5B-7D. In FIG. 26, the six RFID tag circuits 952are arranged in three side-by-side columns with the leftmost columnbeing referred to herein arbitrarily as the first column, the centercolumn being referred to herein arbitrarily as the second column, andthe rightmost column being referred to herein arbitrarily as the thirdcolumn. While only two RFID tag circuits 952 are shown in each of thethree illustrative columns, it should be understood that backing sheet950 continues above and below the depicted circuits 952 of FIG. 26.Backing sheet 950 is flexible, as are inlays 58′, and therefore may besupplied as a roll of material having a multitude of circuits 952thereon arranged in three columns or, in alternative embodiments, moreor less than three columns.

Due to the similarities of inlays 58′ shown in FIG. 26 with inlays 58shown, for example, in FIGS. 5A and 5B, the same reference numbers areused to denote like portions of inlays 58, 58′. Thus, inlays 58′ eachinclude a pair of large antenna patches 64, a first undulated trace 66interconnecting patches 64, a first electrical contact pad 68, a secondelectrical contact pad 70, a second undulated trace 72 extending fromcontact pad 68 toward contact pad 70, and a third undulated trace 74extending from contact pad 70 toward contact pad 68. However, unlikeinlays 58, inlays 58′ include a substantially straight, inclined segment954 that interconnects the respective electrical contact pads 70 withthe associated undulated trace 74. Similar to inlays 58, inlays 58′include a substantially straight segment 955 extending substantiallyhorizontally when inlays 58′ are oriented as shown in FIGS. 26 and 27.Segments 955 interconnect the respective electrical contact pad 68 withthe associated undulated trace 72.

In the illustrative example, pads 70 on the left side of inlays 58′ areoffset upwardly with respect to the pads 68 on the right side of inlays58′ (when the inlays 58′ are oriented as depicted in FIG. 26). As aresult of this inlay geometry, the RFID electrical inlays 58′ ofadjacent columns are arranged on the backing sheet 950 so that, forexample, the right pads 68 of the first column are substantiallyvertically aligned with the left pads 70 of the second column such thatthe right and left pads 68, 70 of the first and second columns,respectively, are spaced apart and alternate vertically along ahypothetical line 956 that extends through the right and left pads 68,70 of the first and second columns. The right and left pads 68, 70 ofthe inlays 58′ of the second and third columns are aligned verticallyand alternate in a similar manner.

Still referring to FIG. 26, pads 70 are situated relative to antennapatches 64 such that that the left pad 70 of each RFID electrical inlay58′ is located beside the left antenna patch 64 whereby a hypotheticalline 958, which is substantially perpendicular to hypothetical line 956,extends through a center of the left pad 70 and intersects the antennapatches 64 which comprise the antenna of the respective inlay 58′.Furthermore, the right pad 68 of each RFID electrical inlay 58′ islocated such that a hypothetical line 960, which is also substantiallyperpendicular to the hypothetical line 956, extends through a center ofthe right pad 68 and does not intersect the antenna patches 64 of therespective inlay 58′.

During manufacture of the RFID tags having inlays 58′ stripes ofconductive adhesive 962 are applied to backing sheet 950 over therespective electrical contact pads 68, 70. The stripes of conductiveadhesive 962 are about twice as wide as electrical contact pads 68, 70in the illustrative example FIG. 26. In other embodiments, the width ofthe stripes of conductive adhesive 962 is less wide or wider, asdesired. After the conductive adhesive 962 is applied to backing sheet950, the backing sheet 950 is cut to separate the columns of inlays 58′from each other. According to this disclosure, a cut pattern or cutline964 weaves back and forth through each stripe of conductive adhesive962. In the embodiment of FIG. 26, the cutline 964 is substantiallysinusoidal in shape. The sinusoidal cutlines 964 are in phase in thestripes of conductive adhesive 962 such that the peaks of the sinusoidalcutlines 964 are aligned with each other horizontally and the valleys ofsinusoidal cutlines 964 are aligned with each other horizontally.

In the stripes of electrically conductive adhesive 962 between the firstand second columns, and between the second and third columns, thesinusoidal cutlines 964 weave back and forth between the alternatingelectrical contact pads 68, 70. The geometry of the sinusoidal cutlines964 is such that contact pad 68 of each inlay 58′ is located adjacent avalley of the adjacent sinusoidal cutline 964 and the associatedelectrical contact pad 70 of the same inlay 58′ is located adjacent apeak of the adjacent sinusoidal cutline 964. By aligning electricalcontact pads 68, 70 in between the first and second columns, and inbetween the second and third columns, and by having a cut pattern 964that weaves back and forth between the electrical contact pads 68, 70, asavings in the amount of electrically conductive adhesive being used isachieved as compared to other arrangements, such as that shown in FIG.5A, that do not have any of the electrical contact pads 68, 70 alignedin adjacent columns.

Referring now to FIG. 27, after the columns are separated from eachother along the cutlines 964, a set of lateral cuts or cutlines 966above and below the respective RFID tag circuits 952 are made widthwiseto separate the circuits 952 from each other. In the illustrativeexample, the lateral cuts 966 are straight but other shapes of lateralcutlines 966 may be used in other embodiments. In some embodiments, thethree separated columns of RFID tag circuits 952 are each placed on awider backing sheet or layer 968 after the substantially sinusoidal cuts964 shown in FIG. 26 have been made. In such embodiments, the lateralcuts 966 extend all the way across the wider backing layer 968 betweenopposite edges 970 of the layer 968. Thus, although only one column ofcircuits 952 are shown in FIG. 27 with an optional backing sheet 968, itshould be appreciated that all three columns from FIG. 26 are handledsimilarly after separation from each other.

Although the embodiment of FIGS. 26 and 27 are shown with sinusoidalshaped cutlines 964, the present disclosure contemplates cutlines ofother shapes. For example, as shown in FIG. 28, a square wave cutline964′ may be used if desired. A rectangular wave is also considered to bewithin the scope of the term “square wave” according to this disclosure.Thus, any stepped pattern using right angle cut patterns similar tocutline 964′ of FIG. 28 is considered to be a “square wave” cutlineherein. As another example of an alternative embodiment, a triangle wavecutline 964″ may be used as shown in FIG. 29. Although FIGS. 28 and 29show the alternative cutlines 964′, 964″ weaving back and forth withinthe stripes of electrically conductive adhesive 962 between the aligned,alternating electrical contact pads 68, 70, it should be appreciatedthat these same shaped cutlines 964′, 964″, respectively, may be usedfor the outside stripes of electrically conductive adhesive 962 havingonly pads 68 or only pads 70, as the case may be.

Referring now to FIG. 30, another alternative is shown in whichelectrically conductive adhesive 962′ is applied to backing sheet 950intermittently as dashes or patches of adhesive 962′ rather than as acontinuous stripe of electrically conductive adhesive 962. Theintermittent stripe or patches of adhesive 962′ are applied over therespective electrical contact pads 68, 70, as the case may be, with gapsor spaces of the backing sheet 950 that lack any adhesive separating thepatches of adhesive 962′. A further savings in adhesive material usageis achieved by applying the adhesive 962′ intermittently. In someembodiments, the intermittent patches of adhesive 962′ are applied tothe outermost column edges (e.g., the leftmost edge of the first columnand the rightmost edge of the third column) over respective electricalcontact pads 68, 70, whereas continuous stripes of electricallyconductive adhesive 962 are applied to the two middle stripes ofadhesive that are shared between the first and second columns, andbetween the second and third columns. In other embodiments, all fourstripes of adhesive may be applied intermittently as separated patchesover the respective electrical contact pads 68, 70.

FIGS. 31A-31N show the ornamental features of an incontinence detectionpad according to the present disclosure and may form the basis forfuture design patent applications claiming priority to the presentdisclosure. It is contemplated that surface shading may be added, asdesired, to any portion of any of FIGS. 31A-31N in such future designpatent applications. Furthermore, with regard to such future designpatent applications, it is contemplated that any portions of FIGS.31A-31N that are shown in solid line may be dotted out, as desired, andthat any portions of FIGS. 31A-31N that are shown in dotted line mayinstead be shown in solid line, as desired, such that all combinationsand permutations of solid and dotted line depictions of the incontinencedetection pad of FIGS. 31A-31N, with or without surface shading beingincluded on any portion thereof, are contemplated by this disclosure.

Although certain illustrative embodiments have been described in detailabove, variations and modifications exist within the scope and spirit ofthis disclosure as described and as defined in the following claims.

The invention claimed is:
 1. An antenna inlay of an RFID tag, theantenna inlay comprising an antenna portion, a first electrical contactportion, a second electrical contact portion, the first electricalcontact portion comprising a first electrical lead having a first gapformed therein to provide a first lead segment and a second leadsegment, and a first resistor placed across the gap to electricallyinterconnect the first and second lead segments, wherein the antennainlay is provided in an absorbent article comprising a topsheet made ofa fluid permeable material, a backsheet comprising a first layer offluid impermeable material, a conductive ink pattern provided above thefirst layer and configured to form a first electrode trace and a secondelectrode trace, a passive radio frequency identification (RFID) tagincluding the antenna inlay and attached to the first layer such thatthe first and second electrical contact portions couple to the first andsecond electrode traces, an absorbent core situated between the topsheetand the backsheet, and a fluid filter layer situated so as to inhibit alow volume of fluid from being able to reach the first and/or secondelectrode traces beneath the absorbent core, wherein after fluid of asufficient volume greater than the low volume has passed through thetopsheet, the absorbent core, and the fluid filter layer, an electricalpathway is formed between the first and second electrode traces by thefluid which enables the passive RFID tag to emit a signal indicating anincontinence event has occurred in response to the passive RFID tagbeing excited by external energy.
 2. The antenna inlay of claim 1,wherein the second electrical contact portion comprises a secondelectrical lead having a second gap formed therein to provide a thirdlead segment and a fourth lead segment, and further comprising a secondresistor placed across the second gap to electrically interconnect thethird and fourth lead segments.
 3. The antenna inlay of claim 2, whereinthe second electrical contact portion is configured as a mirror image ofthe first electrical contact portion.
 4. The antenna inlay of claim 2,wherein the antenna portion comprises a first antenna patch and a secondantenna patch.
 5. The antenna inlay of claim 4, wherein the secondantenna patch is configured as a mirror image of the first antennapatch.
 6. The antenna inlay of claim 2, wherein the antenna portion,first electrical contact portion, and the second electrical contactportion are coplanar.
 7. The antenna inlay of claim 2, wherein theantenna portion, first electrical contact portion, and the secondelectrical contact portion comprise a metallic film.
 8. The antennainlay of claim 7, wherein the metallic film comprises aluminum.
 9. Theantenna inlay of claim 7, wherein a thickness of the metallic film isabout 9 micrometers (μm).
 10. The antenna inlay of claim 2, wherein thefirst resistor and the second resistor have substantially equivalentresistances or wherein the first resistor and the second resistor havedifferent resistances.
 11. The antenna inlay of claim 10, wherein theresistance of at least one of the first and second resistors comprisesabout 2.4 Mega Ohms (MΩ).
 12. The antenna inlay of claim 1, wherein theantenna portion comprises a first antenna patch and a second antennapatch.
 13. The antenna inlay of claim 12, wherein the second antennapatch is configured as a mirror image of the first antenna patch. 14.The antenna inlay of claim 1, wherein the antenna portion, firstelectrical contact portion, and the second electrical contact portionare coplanar.
 15. The antenna inlay of claim 1, wherein the antennaportion, first electrical contact portion, and the second electricalcontact portion comprise a metallic film.
 16. The antenna inlay of claim15, wherein the metallic film comprises aluminum.
 17. The antenna inlayof claim 15, wherein a thickness of the metallic film is about 9micrometers (μm).
 18. An antenna inlay of an RFID tag, the antenna inlaycomprising an antenna portion, a first electrical contact portion, asecond electrical contact portion, the first electrical contact portioncomprising a first electrical lead having a first gap formed therein toprovide a first lead segment and a second lead segment, and a firstresistor placed across the gap to electrically interconnect the firstand second lead segments, wherein the antenna inlay is used in a methodof controlling an incontinence detection system, the method comprisingestablishing a first reader antenna of a plurality of reader antennae asa transmit antenna that is used to wirelessly energize a passive RFIDtag of an absorbent article at a first power level, the passive RFID tagincluding the antenna inlay of claim 1, wherein the plurality of readerantennae comprises N spaced apart reader antennae, wherein N is aninteger equal to or greater than three, establishing each of theplurality of reader antennae, except for the first reader antenna, asreceive reader antennae that each listen for backscattered data emittedfrom the passive RFID tag, and reducing the first power level to asecond power level if the receive reader antennae that are able to readthe backscattered data exceeds a predetermined number of receive readerantennae, the predetermined number being less than N−1.
 19. The antennainlay of claim 18, wherein the method further comprises analyzing signalto noise ratio between the transmit antenna and each of the receiveantenna before reducing the first power level to the second power level.20. The antenna inlay of claim 18, wherein the method further comprisesanalyzing a receive signal level (RSL) figure of merit (FoM) of thebackscattered data before reducing the first power level to the secondpower level.
 21. The antenna inlay of claim 20, wherein the RSL FoM ofmultiple emissions of backscattered data are averaged before reducingthe first power level to the second power level.
 22. The antenna inlayof claim 18, wherein the method further comprises determining that anexternal power flag is set in the backscattered data before reducing thefirst power level to the second power level.
 23. The antenna inlay ofclaim 18, wherein the predetermined number of receive antennae comprisestwo receive antennae.
 24. The antenna inlay of claim 18, wherein thepredetermined number of receive antennae comprises one receive antenna.25. The antenna inlay of claim 18, wherein the first power level and thesecond power level lie within a range of about +20 decibel milliWatt(dBm) to about +33 dBm.
 26. The antenna inlay of claim 18, wherein themethod further comprises cycling through the plurality of antennae asbeing established as the transmit antenna with each of the remainingantennae of the plurality of antennae being established as the receiveantenna for a period of time.
 27. The antenna inlay of claim 26, whereinthe plurality of antennae are coupled to a bistatic radio frequency (RF)switch matrix which is operable to establish which antenna of theplurality of antennae is the transmit antenna and to establish whichantenna of the plurality of antennae is the receive antenna.
 28. Theantenna inlay of claim 27, wherein the method further comprisesoperating the bistatic RF switch matrix to cause the transmit antenna totransmit using a frequency hopping scheme.
 29. The antenna inlay ofclaim 28, wherein the frequency hopping scheme uses 50 distinctfrequencies, with each frequency being used only once in a pseudo-randomorder before any of the 50 frequencies are repeated.
 30. The antennainlay of claim 29, wherein the 50 frequencies lie within a range betweenabout 902 MegaHertz (MHz) and 928 MHz.
 31. An antenna inlay of an RFIDtag, the antenna inlay comprising an antenna portion, a first electricalcontact portion, a second electrical contact portion, the firstelectrical contact portion comprising a first electrical lead having afirst gap formed therein to provide a first lead segment and a secondlead segment, and a first resistor placed across the gap to electricallyinterconnect the first and second lead segments, wherein the antennainlay is provided in an absorbent article comprising a substrate, afirst electrode on the substrate, a second electrode on the substrate,the second electrode being spaced from the first electrode, circuitrycoupled to the first and second electrodes, the circuitry including theantenna inlay, the circuitry being operable to monitor whether abiofluid is present on the substrate by determining whether the firstand second electrodes are in an open circuit configuration or a closedcircuit configuration, the open circuit configuration being indicativeof an absence of biofluid and a closed circuit configuration beingindicative of a presence of biofluid, and a plurality of high wickbridges interconnecting the first and second electrodes.
 32. The antennainlay of claim 31, wherein the antenna portion comprises a first antennapatch and a second antenna patch.
 33. The antenna inlay of claim 32,wherein the second antenna patch is configured as a mirror image of thefirst antenna patch.
 34. The antenna inlay of claim 31, wherein theantenna portion, first electrical contact portion, and the secondelectrical contact portion are coplanar.
 35. The antenna inlay of claim31, wherein the antenna portion, first electrical contact portion, andthe second electrical contact portion comprise a metallic film.
 36. Theantenna inlay of claim 35, wherein the metallic film comprises aluminum.37. The antenna inlay of claim 35, wherein a thickness of the metallicfilm is about 9 micrometers (μm).
 38. The antenna inlay of claim 31,wherein the first electrode includes a generally straight first segment,the second electrode includes a generally straight second segment, andat least some of the high wick bridges include a generally straight mainsegment that is substantially perpendicular to the first and secondsegments.
 39. The antenna inlay of claim 31, wherein the at least someof the high wick bridges include a series of hash segments that aresubstantially perpendicular with the main segment.
 40. The antenna inlayof claim 39, wherein the main segment bisects each of the hash segments.41. The antenna inlay of claim 39, wherein the hash segments are ofsubstantially equivalent lengths.
 42. The antenna inlay of claim 41,further comprising a hydrophobic material situated within each of aplurality of zones bounded by respective portions of the first andsecond electrodes and by respective pairs of adjacent high wick bridges.43. The antenna inlay of claim 42, wherein the hydrophobic materialcomprises a hydrophobic coating.
 44. The antenna inlay of claim 42,wherein the hydrophobic material in at least some of the zones isquadrilateral in shape.
 45. The antenna inlay of claim 42, wherein eachof the high wick brides includes a main segment and a series of hashsegments extending across the main segment, wherein ends of the hashsegments terminate at or in close proximity to a respective boundary ofthe hydrophobic material in each zone.
 46. The antenna inlay of claim31, wherein the RFID tag comprises a passive RFID tag.